CVE-2026-27651 (GCVE-0-2026-27651)
Vulnerability from cvelistv5
Published
2026-03-24 14:13
Modified
2026-07-15 01:13
Severity ?
7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
8.7 (High) - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CWE
  • CWE-476 - NULL Pointer Dereference
Summary
When the ngx_mail_auth_http_module module is enabled on NGINX Plus or NGINX Open Source, undisclosed requests can cause worker processes to terminate. This issue may occur when (1) CRAM-MD5 or APOP authentication is enabled, and (2) the authentication server permits retry by returning the Auth-Wait response header. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
References
Impacted products
Vendor Product Version
F5 NGINX Open Source Version: 1.29.0   ≤
Version: 0.5.15   ≤
Create a notification for this product.
   F5 NGINX Plus Version: R36   < R36 P3
Version: R35   < R35 P2
Version: R34   < *
Version: R33   < *
Version: R32   < R32 P5
 Create a notification for this product.
Show details on NVD website

To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-27651",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-03-24T15:02:03.137056Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-03-24T15:14:13.220Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      },
      {
        "affected": [
          {
            "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
            "cpes": [
              "cpe:/o:redhat:enterprise_linux:10.1"
            ],
            "defaultStatus": "affected",
            "packageName": "nginx",
            "product": "Red Hat Enterprise Linux 10",
            "vendor": "Red Hat",
            "versions": [
              {
                "lessThan": "*",
                "status": "unaffected",
                "version": "2:1.26.3-2.el10_1.1",
                "versionType": "rpm"
              }
            ]
          },
          {
            "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
            "cpes": [
              "cpe:/o:redhat:enterprise_linux_eus:10.0"
            ],
            "defaultStatus": "affected",
            "packageName": "nginx",
            "product": "Red Hat Enterprise Linux 10.0 Extended Update Support",
            "vendor": "Red Hat",
            "versions": [
              {
                "lessThan": "*",
                "status": "unaffected",
                "version": "2:1.26.3-1.el10_0.8",
                "versionType": "rpm"
              }
            ]
          },
          {
            "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
            "cpes": [
              "cpe:/a:redhat:enterprise_linux:8"
            ],
            "defaultStatus": "affected",
            "packageName": "nginx:1.24",
            "product": "Red Hat Enterprise Linux 8",
            "vendor": "Red Hat",
            "versions": [
              {
                "lessThan": "*",
                "status": "unaffected",
                "version": "8100020260401080144.489197e6",
                "versionType": "rpm"
              }
            ]
          },
          {
            "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
            "cpes": [
              "cpe:/a:redhat:enterprise_linux:9"
            ],
            "defaultStatus": "affected",
            "packageName": "nginx:1.24",
            "product": "Red Hat Enterprise Linux 9",
            "vendor": "Red Hat",
            "versions": [
              {
                "lessThan": "*",
                "status": "unaffected",
                "version": "9070020260331134728.9",
                "versionType": "rpm"
              }
            ]
          },
          {
            "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
            "cpes": [
              "cpe:/a:redhat:enterprise_linux:9"
            ],
            "defaultStatus": "affected",
            "packageName": "nginx",
            "product": "Red Hat Enterprise Linux 9",
            "vendor": "Red Hat",
            "versions": [
              {
                "lessThan": "*",
                "status": "unaffected",
                "version": "2:1.20.1-24.el9_7.2",
                "versionType": "rpm"
              }
            ]
          },
          {
            "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
            "cpes": [
              "cpe:/a:redhat:enterprise_linux:9"
            ],
            "defaultStatus": "affected",
            "packageName": "nginx:1.26",
            "product": "Red Hat Enterprise Linux 9",
            "vendor": "Red Hat",
            "versions": [
              {
                "lessThan": "*",
                "status": "unaffected",
                "version": "9070020260407080353.9",
                "versionType": "rpm"
              }
            ]
          },
          {
            "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
            "cpes": [
              "cpe:/a:redhat:rhel_e4s:9.0"
            ],
            "defaultStatus": "affected",
            "packageName": "nginx",
            "product": "Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions",
            "vendor": "Red Hat",
            "versions": [
              {
                "lessThan": "*",
                "status": "unaffected",
                "version": "1:1.20.1-10.el9_0.3",
                "versionType": "rpm"
              }
            ]
          },
          {
            "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
            "cpes": [
              "cpe:/a:redhat:rhel_e4s:9.2"
            ],
            "defaultStatus": "affected",
            "packageName": "nginx",
            "product": "Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions",
            "vendor": "Red Hat",
            "versions": [
              {
                "lessThan": "*",
                "status": "unaffected",
                "version": "1:1.20.1-14.el9_2.5",
                "versionType": "rpm"
              }
            ]
          },
          {
            "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
            "cpes": [
              "cpe:/a:redhat:rhel_eus:9.4"
            ],
            "defaultStatus": "affected",
            "packageName": "nginx",
            "product": "Red Hat Enterprise Linux 9.4 Extended Update Support",
            "vendor": "Red Hat",
            "versions": [
              {
                "lessThan": "*",
                "status": "unaffected",
                "version": "1:1.20.1-16.el9_4.5",
                "versionType": "rpm"
              }
            ]
          },
          {
            "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
            "cpes": [
              "cpe:/a:redhat:rhel_eus:9.4"
            ],
            "defaultStatus": "affected",
            "packageName": "nginx:1.24",
            "product": "Red Hat Enterprise Linux 9.4 Extended Update Support",
            "vendor": "Red Hat",
            "versions": [
              {
                "lessThan": "*",
                "status": "unaffected",
                "version": "9040020260504195322.9",
                "versionType": "rpm"
              }
            ]
          },
          {
            "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
            "cpes": [
              "cpe:/a:redhat:rhel_eus:9.6"
            ],
            "defaultStatus": "affected",
            "packageName": "nginx",
            "product": "Red Hat Enterprise Linux 9.6 Extended Update Support",
            "vendor": "Red Hat",
            "versions": [
              {
                "lessThan": "*",
                "status": "unaffected",
                "version": "2:1.20.1-22.el9_6.5",
                "versionType": "rpm"
              }
            ]
          },
          {
            "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
            "cpes": [
              "cpe:/a:redhat:rhel_eus:9.6"
            ],
            "defaultStatus": "affected",
            "packageName": "nginx:1.24",
            "product": "Red Hat Enterprise Linux 9.6 Extended Update Support",
            "vendor": "Red Hat",
            "versions": [
              {
                "lessThan": "*",
                "status": "unaffected",
                "version": "9060020260504194843.9",
                "versionType": "rpm"
              }
            ]
          },
          {
            "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
            "cpes": [
              "cpe:/a:redhat:rhel_eus:9.6"
            ],
            "defaultStatus": "affected",
            "packageName": "nginx:1.26",
            "product": "Red Hat Enterprise Linux 9.6 Extended Update Support",
            "vendor": "Red Hat",
            "versions": [
              {
                "lessThan": "*",
                "status": "unaffected",
                "version": "9060020260504154614.9",
                "versionType": "rpm"
              }
            ]
          },
          {
            "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
            "cpes": [
              "cpe:/a:redhat:hummingbird:1"
            ],
            "defaultStatus": "affected",
            "packageName": "nginx-main",
            "product": "Red Hat Hardened Images",
            "vendor": "Red Hat",
            "versions": [
              {
                "lessThan": "*",
                "status": "unaffected",
                "version": "1.30.0-1.hum1",
                "versionType": "rpm"
              }
            ]
          },
          {
            "collectionURL": "https://catalog.redhat.com/software/containers/",
            "cpes": [
              "cpe:/a:redhat:rhui:5::el9"
            ],
            "defaultStatus": "affected",
            "packageName": "rhui5/cds-rhel9",
            "product": "Red Hat Update Infrastructure 5",
            "vendor": "Red Hat",
            "versions": [
              {
                "lessThan": "*",
                "status": "unaffected",
                "version": "1776868774",
                "versionType": "rpm"
              }
            ]
          },
          {
            "collectionURL": "https://catalog.redhat.com/software/containers/",
            "cpes": [
              "cpe:/a:redhat:rhui:5::el9"
            ],
            "defaultStatus": "affected",
            "packageName": "rhui5/rhua-rhel9",
            "product": "Red Hat Update Infrastructure 5",
            "vendor": "Red Hat",
            "versions": [
              {
                "lessThan": "*",
                "status": "unaffected",
                "version": "1776868842",
                "versionType": "rpm"
              }
            ]
          }
        ],
        "datePublic": "2026-03-24T14:13:27.295Z",
        "descriptions": [
          {
            "lang": "en",
            "value": "A flaw was found in NGINX, specifically within the ngx_mail_auth_http_module. When this module is enabled, and CRAM-MD5 or APOP authentication is active with an authentication server that permits retries, undisclosed requests can cause NGINX worker processes to terminate. This can lead to a Denial of Service (DoS), making the affected NGINX instance unavailable to legitimate users."
          }
        ],
        "metrics": [
          {
            "other": {
              "content": {
                "namespace": "https://access.redhat.com/security/updates/classification/",
                "value": "Important"
              },
              "type": "Red Hat severity rating"
            }
          },
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "HIGH",
              "baseScore": 7.5,
              "baseSeverity": "HIGH",
              "confidentialityImpact": "NONE",
              "integrityImpact": "NONE",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
              "version": "3.1"
            },
            "format": "CVSS"
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-476",
                "description": "NULL Pointer Dereference",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-07-15T01:13:39.490Z",
          "orgId": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
          "shortName": "redhat-SADP"
        },
        "references": [
          {
            "tags": [
              "vdb-entry",
              "x_refsource_REDHAT"
            ],
            "url": "https://access.redhat.com/security/cve/CVE-2026-27651"
          },
          {
            "name": "RHBZ#2450791",
            "tags": [
              "issue-tracking",
              "x_refsource_REDHAT"
            ],
            "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2450791"
          },
          {
            "tags": [
              "x_sadp-csaf-vex"
            ],
            "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-27651.json"
          },
          {
            "tags": [
              "vendor-advisory",
              "x_refsource_REDHAT"
            ],
            "url": "https://access.redhat.com/errata/RHSA-2026:13634"
          },
          {
            "tags": [
              "vendor-advisory",
              "x_refsource_REDHAT"
            ],
            "url": "https://access.redhat.com/errata/RHSA-2026:6906"
          },
          {
            "tags": [
              "vendor-advisory",
              "x_refsource_REDHAT"
            ],
            "url": "https://access.redhat.com/errata/RHSA-2026:6907"
          },
          {
            "tags": [
              "vendor-advisory",
              "x_refsource_REDHAT"
            ],
            "url": "https://access.redhat.com/errata/RHSA-2026:15942"
          },
          {
            "tags": [
              "vendor-advisory",
              "x_refsource_REDHAT"
            ],
            "url": "https://access.redhat.com/errata/RHSA-2026:14836"
          },
          {
            "tags": [
              "vendor-advisory",
              "x_refsource_REDHAT"
            ],
            "url": "https://access.redhat.com/errata/RHSA-2026:13839"
          },
          {
            "tags": [
              "vendor-advisory",
              "x_refsource_REDHAT"
            ],
            "url": "https://access.redhat.com/errata/RHSA-2026:15943"
          },
          {
            "tags": [
              "vendor-advisory",
              "x_refsource_REDHAT"
            ],
            "url": "https://access.redhat.com/errata/RHSA-2026:15945"
          },
          {
            "tags": [
              "vendor-advisory",
              "x_refsource_REDHAT"
            ],
            "url": "https://access.redhat.com/errata/RHSA-2026:13680"
          },
          {
            "tags": [
              "vendor-advisory",
              "x_refsource_REDHAT"
            ],
            "url": "https://access.redhat.com/errata/RHSA-2026:15966"
          },
          {
            "tags": [
              "vendor-advisory",
              "x_refsource_REDHAT"
            ],
            "url": "https://access.redhat.com/errata/RHSA-2026:6923"
          },
          {
            "tags": [
              "vendor-advisory",
              "x_refsource_REDHAT"
            ],
            "url": "https://access.redhat.com/errata/RHSA-2026:7002"
          },
          {
            "tags": [
              "vendor-advisory",
              "x_refsource_REDHAT"
            ],
            "url": "https://access.redhat.com/errata/RHSA-2026:7343"
          },
          {
            "tags": [
              "vendor-advisory",
              "x_refsource_REDHAT"
            ],
            "url": "https://access.redhat.com/errata/RHSA-2026:8346"
          },
          {
            "tags": [
              "vendor-advisory",
              "x_refsource_REDHAT"
            ],
            "url": "https://access.redhat.com/errata/RHSA-2026:10065"
          }
        ],
        "solutions": [
          {
            "lang": "en",
            "value": "RHSA-2026:13634: Red Hat Enterprise Linux AppStream EUS (v. 10.0), Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0)"
          },
          {
            "lang": "en",
            "value": "RHSA-2026:6906: Red Hat Enterprise Linux AppStream (v. 10)"
          },
          {
            "lang": "en",
            "value": "RHSA-2026:6907: Red Hat Enterprise Linux AppStream (v. 8)"
          },
          {
            "lang": "en",
            "value": "RHSA-2026:15942: Red Hat Enterprise Linux AppStream E4S (v.9.0)"
          },
          {
            "lang": "en",
            "value": "RHSA-2026:14836: Red Hat Enterprise Linux AppStream E4S (v.9.2)"
          },
          {
            "lang": "en",
            "value": "RHSA-2026:13839: Red Hat CodeReady Linux Builder EUS (v.9.4), Red Hat Enterprise Linux AppStream EUS (v.9.4)"
          },
          {
            "lang": "en",
            "value": "RHSA-2026:15943: Red Hat Enterprise Linux AppStream EUS (v.9.4)"
          },
          {
            "lang": "en",
            "value": "RHSA-2026:15945: Red Hat Enterprise Linux AppStream EUS (v.9.6)"
          },
          {
            "lang": "en",
            "value": "RHSA-2026:13680: Red Hat CodeReady Linux Builder EUS (v.9.6), Red Hat Enterprise Linux AppStream EUS (v.9.6)"
          },
          {
            "lang": "en",
            "value": "RHSA-2026:15966: Red Hat Enterprise Linux AppStream EUS (v.9.6)"
          },
          {
            "lang": "en",
            "value": "RHSA-2026:6923: Red Hat Enterprise Linux AppStream (v. 9)"
          },
          {
            "lang": "en",
            "value": "RHSA-2026:7002: Red Hat Enterprise Linux AppStream (v. 9)"
          },
          {
            "lang": "en",
            "value": "RHSA-2026:7343: Red Hat Enterprise Linux AppStream (v. 9)"
          },
          {
            "lang": "en",
            "value": "RHSA-2026:8346: Red Hat Hardened Images"
          },
          {
            "lang": "en",
            "value": "RHSA-2026:10065: Red Hat Update Infrastructure 5"
          }
        ],
        "timeline": [
          {
            "lang": "en",
            "time": "2026-03-24T15:02:32.414Z",
            "value": "Reported to Red Hat."
          },
          {
            "lang": "en",
            "time": "2026-03-24T14:13:27.295Z",
            "value": "Made public."
          }
        ],
        "title": "NGINX: NGINX: Denial of Service via undisclosed requests when ngx_mail_auth_http_module is enabled",
        "workarounds": [
          {
            "lang": "en",
            "value": "Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability."
          }
        ],
        "x_adpType": "supplier",
        "x_generator": {
          "engine": "sadp-cli 1.0.0"
        }
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unknown",
          "modules": [
            "ngx_mail_auth_http_module"
          ],
          "product": "NGINX Open Source",
          "vendor": "F5",
          "versions": [
            {
              "lessThan": "1.29.7",
              "status": "affected",
              "version": "1.29.0",
              "versionType": "semver"
            },
            {
              "lessThan": "1.28.3",
              "status": "affected",
              "version": "0.5.15",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "unaffected",
          "modules": [
            "ngx_mail_auth_http_module"
          ],
          "product": "NGINX Plus",
          "vendor": "F5",
          "versions": [
            {
              "lessThan": "R36 P3",
              "status": "affected",
              "version": "R36",
              "versionType": "custom"
            },
            {
              "lessThan": "R35 P2",
              "status": "affected",
              "version": "R35",
              "versionType": "custom"
            },
            {
              "lessThan": "*",
              "status": "affected",
              "version": "R34",
              "versionType": "custom"
            },
            {
              "lessThan": "*",
              "status": "affected",
              "version": "R33",
              "versionType": "custom"
            },
            {
              "lessThan": "R32 P5",
              "status": "affected",
              "version": "R32",
              "versionType": "custom"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "reporter",
          "value": "F5 acknowledges Arkadi Vainbrand for bringing this issue to our attention and following the highest standards of coordinated disclosure."
        }
      ],
      "datePublic": "2026-03-24T14:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "\u003cspan style=\"background-color: rgb(255, 255, 255);\"\u003eWhen the \u003c/span\u003e\u003cstrong\u003engx_mail_auth_http_module\u003c/strong\u003e\u003cspan style=\"background-color: rgb(255, 255, 255);\"\u003e\u0026nbsp;module is enabled on NGINX Plus or NGINX Open Source, undisclosed requests can cause worker processes to terminate. This issue may occur when (1) CRAM-MD5 or APOP authentication is enabled, and (2) the authentication server permits retry by returning the Auth-Wait response header.\u003c/span\u003e Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated."
            }
          ],
          "value": "When the ngx_mail_auth_http_module\u00a0module is enabled on NGINX Plus or NGINX Open Source, undisclosed requests can cause worker processes to terminate. This issue may occur when (1) CRAM-MD5 or APOP authentication is enabled, and (2) the authentication server permits retry by returning the Auth-Wait response header. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        },
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 8.7,
            "baseSeverity": "HIGH",
            "privilegesRequired": "NONE",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "NONE",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-476",
              "description": "CWE-476 NULL Pointer Dereference",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-03-24T14:22:35.756Z",
        "orgId": "9dacffd4-cb11-413f-8451-fbbfd4ddc0ab",
        "shortName": "f5"
      },
      "references": [
        {
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://my.f5.com/manage/s/article/K000160383"
        }
      ],
      "source": {
        "discovery": "EXTERNAL"
      },
      "title": "NGINX ngx_mail_auth_http_module vulnerability",
      "x_generator": {
        "engine": "F5 SIRTBot v1.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "9dacffd4-cb11-413f-8451-fbbfd4ddc0ab",
    "assignerShortName": "f5",
    "cveId": "CVE-2026-27651",
    "datePublished": "2026-03-24T14:13:27.295Z",
    "dateReserved": "2026-03-18T16:06:38.454Z",
    "dateUpdated": "2026-07-15T01:13:39.490Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"NGINX: NGINX: Denial of Service via undisclosed requests when ngx_mail_auth_http_module is enabled\", \"metrics\": [{\"other\": {\"type\": \"Red Hat severity rating\", \"content\": {\"value\": \"Important\", \"namespace\": \"https://access.redhat.com/security/updates/classification/\"}}}, {\"format\": \"CVSS\", \"cvssV3_1\": {\"scope\": \"UNCHANGED\", \"version\": \"3.1\", \"baseScore\": 7.5, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"HIGH\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H\", \"integrityImpact\": \"NONE\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"HIGH\", \"privilegesRequired\": \"NONE\", \"confidentialityImpact\": \"NONE\"}}], \"affected\": [{\"cpes\": [\"cpe:/o:redhat:enterprise_linux:10.1\"], \"vendor\": \"Red Hat\", \"product\": \"Red Hat Enterprise Linux 10\", \"versions\": [{\"status\": \"unaffected\", \"version\": \"2:1.26.3-2.el10_1.1\", \"lessThan\": \"*\", \"versionType\": \"rpm\"}], \"packageName\": \"nginx\", \"collectionURL\": \"https://access.redhat.com/downloads/content/package-browser/\", \"defaultStatus\": \"affected\"}, {\"cpes\": [\"cpe:/o:redhat:enterprise_linux_eus:10.0\"], \"vendor\": \"Red Hat\", \"product\": \"Red Hat Enterprise Linux 10.0 Extended Update Support\", \"versions\": [{\"status\": \"unaffected\", \"version\": \"2:1.26.3-1.el10_0.8\", \"lessThan\": \"*\", \"versionType\": \"rpm\"}], \"packageName\": \"nginx\", \"collectionURL\": \"https://access.redhat.com/downloads/content/package-browser/\", \"defaultStatus\": \"affected\"}, {\"cpes\": [\"cpe:/a:redhat:enterprise_linux:8\"], \"vendor\": \"Red Hat\", \"product\": \"Red Hat Enterprise Linux 8\", \"versions\": [{\"status\": \"unaffected\", \"version\": \"8100020260401080144.489197e6\", \"lessThan\": \"*\", \"versionType\": \"rpm\"}], \"packageName\": \"nginx:1.24\", \"collectionURL\": \"https://access.redhat.com/downloads/content/package-browser/\", \"defaultStatus\": \"affected\"}, {\"cpes\": [\"cpe:/a:redhat:enterprise_linux:9\"], \"vendor\": \"Red Hat\", \"product\": \"Red Hat Enterprise Linux 9\", \"versions\": [{\"status\": \"unaffected\", \"version\": \"9070020260331134728.9\", \"lessThan\": \"*\", \"versionType\": \"rpm\"}], \"packageName\": \"nginx:1.24\", \"collectionURL\": \"https://access.redhat.com/downloads/content/package-browser/\", \"defaultStatus\": \"affected\"}, {\"cpes\": [\"cpe:/a:redhat:enterprise_linux:9\"], \"vendor\": \"Red Hat\", \"product\": \"Red Hat Enterprise Linux 9\", \"versions\": [{\"status\": \"unaffected\", \"version\": \"2:1.20.1-24.el9_7.2\", \"lessThan\": \"*\", \"versionType\": \"rpm\"}], \"packageName\": \"nginx\", \"collectionURL\": \"https://access.redhat.com/downloads/content/package-browser/\", \"defaultStatus\": \"affected\"}, {\"cpes\": [\"cpe:/a:redhat:enterprise_linux:9\"], \"vendor\": \"Red Hat\", \"product\": \"Red Hat Enterprise Linux 9\", \"versions\": [{\"status\": \"unaffected\", \"version\": \"9070020260407080353.9\", \"lessThan\": \"*\", \"versionType\": \"rpm\"}], \"packageName\": \"nginx:1.26\", \"collectionURL\": \"https://access.redhat.com/downloads/content/package-browser/\", \"defaultStatus\": \"affected\"}, {\"cpes\": [\"cpe:/a:redhat:rhel_e4s:9.0\"], \"vendor\": \"Red Hat\", \"product\": \"Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions\", \"versions\": [{\"status\": \"unaffected\", \"version\": \"1:1.20.1-10.el9_0.3\", \"lessThan\": \"*\", \"versionType\": \"rpm\"}], \"packageName\": \"nginx\", \"collectionURL\": \"https://access.redhat.com/downloads/content/package-browser/\", \"defaultStatus\": \"affected\"}, {\"cpes\": [\"cpe:/a:redhat:rhel_e4s:9.2\"], \"vendor\": \"Red Hat\", \"product\": \"Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions\", \"versions\": [{\"status\": \"unaffected\", \"version\": \"1:1.20.1-14.el9_2.5\", \"lessThan\": \"*\", \"versionType\": \"rpm\"}], \"packageName\": \"nginx\", \"collectionURL\": \"https://access.redhat.com/downloads/content/package-browser/\", \"defaultStatus\": \"affected\"}, {\"cpes\": [\"cpe:/a:redhat:rhel_eus:9.4\"], \"vendor\": \"Red Hat\", \"product\": \"Red Hat Enterprise Linux 9.4 Extended Update Support\", \"versions\": [{\"status\": \"unaffected\", \"version\": \"1:1.20.1-16.el9_4.5\", \"lessThan\": \"*\", \"versionType\": \"rpm\"}], \"packageName\": \"nginx\", \"collectionURL\": \"https://access.redhat.com/downloads/content/package-browser/\", \"defaultStatus\": \"affected\"}, {\"cpes\": [\"cpe:/a:redhat:rhel_eus:9.4\"], \"vendor\": \"Red Hat\", \"product\": \"Red Hat Enterprise Linux 9.4 Extended Update Support\", \"versions\": [{\"status\": \"unaffected\", \"version\": \"9040020260504195322.9\", \"lessThan\": \"*\", \"versionType\": \"rpm\"}], \"packageName\": \"nginx:1.24\", \"collectionURL\": \"https://access.redhat.com/downloads/content/package-browser/\", \"defaultStatus\": \"affected\"}, {\"cpes\": [\"cpe:/a:redhat:rhel_eus:9.6\"], \"vendor\": \"Red Hat\", \"product\": \"Red Hat Enterprise Linux 9.6 Extended Update Support\", \"versions\": [{\"status\": \"unaffected\", \"version\": \"2:1.20.1-22.el9_6.5\", \"lessThan\": \"*\", \"versionType\": \"rpm\"}], \"packageName\": \"nginx\", \"collectionURL\": \"https://access.redhat.com/downloads/content/package-browser/\", \"defaultStatus\": \"affected\"}, {\"cpes\": [\"cpe:/a:redhat:rhel_eus:9.6\"], \"vendor\": \"Red Hat\", \"product\": \"Red Hat Enterprise Linux 9.6 Extended Update Support\", \"versions\": [{\"status\": \"unaffected\", \"version\": \"9060020260504194843.9\", \"lessThan\": \"*\", \"versionType\": \"rpm\"}], \"packageName\": \"nginx:1.24\", \"collectionURL\": \"https://access.redhat.com/downloads/content/package-browser/\", \"defaultStatus\": \"affected\"}, {\"cpes\": [\"cpe:/a:redhat:rhel_eus:9.6\"], \"vendor\": \"Red Hat\", \"product\": \"Red Hat Enterprise Linux 9.6 Extended Update Support\", \"versions\": [{\"status\": \"unaffected\", \"version\": \"9060020260504154614.9\", \"lessThan\": \"*\", \"versionType\": \"rpm\"}], \"packageName\": \"nginx:1.26\", \"collectionURL\": \"https://access.redhat.com/downloads/content/package-browser/\", \"defaultStatus\": \"affected\"}, {\"cpes\": [\"cpe:/a:redhat:hummingbird:1\"], \"vendor\": \"Red Hat\", \"product\": \"Red Hat Hardened Images\", \"versions\": [{\"status\": \"unaffected\", \"version\": \"1.30.0-1.hum1\", \"lessThan\": \"*\", \"versionType\": \"rpm\"}], \"packageName\": \"nginx-main\", \"collectionURL\": \"https://access.redhat.com/downloads/content/package-browser/\", \"defaultStatus\": \"affected\"}, {\"cpes\": [\"cpe:/a:redhat:rhui:5::el9\"], \"vendor\": \"Red Hat\", \"product\": \"Red Hat Update Infrastructure 5\", \"versions\": [{\"status\": \"unaffected\", \"version\": \"1776868774\", \"lessThan\": \"*\", \"versionType\": \"rpm\"}], \"packageName\": \"rhui5/cds-rhel9\", \"collectionURL\": \"https://catalog.redhat.com/software/containers/\", \"defaultStatus\": \"affected\"}, {\"cpes\": [\"cpe:/a:redhat:rhui:5::el9\"], \"vendor\": \"Red Hat\", \"product\": \"Red Hat Update Infrastructure 5\", \"versions\": [{\"status\": \"unaffected\", \"version\": \"1776868842\", \"lessThan\": \"*\", \"versionType\": \"rpm\"}], \"packageName\": \"rhui5/rhua-rhel9\", \"collectionURL\": \"https://catalog.redhat.com/software/containers/\", \"defaultStatus\": \"affected\"}], \"timeline\": [{\"lang\": \"en\", \"time\": \"2026-03-24T15:02:32.414Z\", \"value\": \"Reported to Red Hat.\"}, {\"lang\": \"en\", \"time\": \"2026-03-24T14:13:27.295Z\", \"value\": \"Made public.\"}], \"solutions\": [{\"lang\": \"en\", \"value\": \"RHSA-2026:13634: Red Hat Enterprise Linux AppStream EUS (v. 10.0), Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0)\"}, {\"lang\": \"en\", \"value\": \"RHSA-2026:6906: Red Hat Enterprise Linux AppStream (v. 10)\"}, {\"lang\": \"en\", \"value\": \"RHSA-2026:6907: Red Hat Enterprise Linux AppStream (v. 8)\"}, {\"lang\": \"en\", \"value\": \"RHSA-2026:15942: Red Hat Enterprise Linux AppStream E4S (v.9.0)\"}, {\"lang\": \"en\", \"value\": \"RHSA-2026:14836: Red Hat Enterprise Linux AppStream E4S (v.9.2)\"}, {\"lang\": \"en\", \"value\": \"RHSA-2026:13839: Red Hat CodeReady Linux Builder EUS (v.9.4), Red Hat Enterprise Linux AppStream EUS (v.9.4)\"}, {\"lang\": \"en\", \"value\": \"RHSA-2026:15943: Red Hat Enterprise Linux AppStream EUS (v.9.4)\"}, {\"lang\": \"en\", \"value\": \"RHSA-2026:15945: Red Hat Enterprise Linux AppStream EUS (v.9.6)\"}, {\"lang\": \"en\", \"value\": \"RHSA-2026:13680: Red Hat CodeReady Linux Builder EUS (v.9.6), Red Hat Enterprise Linux AppStream EUS (v.9.6)\"}, {\"lang\": \"en\", \"value\": \"RHSA-2026:15966: Red Hat Enterprise Linux AppStream EUS (v.9.6)\"}, {\"lang\": \"en\", \"value\": \"RHSA-2026:6923: Red Hat Enterprise Linux AppStream (v. 9)\"}, {\"lang\": \"en\", \"value\": \"RHSA-2026:7002: Red Hat Enterprise Linux AppStream (v. 9)\"}, {\"lang\": \"en\", \"value\": \"RHSA-2026:7343: Red Hat Enterprise Linux AppStream (v. 9)\"}, {\"lang\": \"en\", \"value\": \"RHSA-2026:8346: Red Hat Hardened Images\"}, {\"lang\": \"en\", \"value\": \"RHSA-2026:10065: Red Hat Update Infrastructure 5\"}], \"x_adpType\": \"supplier\", \"datePublic\": \"2026-03-24T14:13:27.295Z\", \"references\": [{\"url\": \"https://access.redhat.com/security/cve/CVE-2026-27651\", \"tags\": [\"vdb-entry\", \"x_refsource_REDHAT\"]}, {\"url\": \"https://bugzilla.redhat.com/show_bug.cgi?id=2450791\", \"name\": \"RHBZ#2450791\", \"tags\": [\"issue-tracking\", \"x_refsource_REDHAT\"]}, {\"url\": \"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-27651.json\", \"tags\": [\"x_sadp-csaf-vex\"]}, {\"url\": \"https://access.redhat.com/errata/RHSA-2026:13634\", \"tags\": [\"vendor-advisory\", \"x_refsource_REDHAT\"]}, {\"url\": \"https://access.redhat.com/errata/RHSA-2026:6906\", \"tags\": [\"vendor-advisory\", \"x_refsource_REDHAT\"]}, {\"url\": \"https://access.redhat.com/errata/RHSA-2026:6907\", \"tags\": [\"vendor-advisory\", \"x_refsource_REDHAT\"]}, {\"url\": \"https://access.redhat.com/errata/RHSA-2026:15942\", \"tags\": [\"vendor-advisory\", \"x_refsource_REDHAT\"]}, {\"url\": \"https://access.redhat.com/errata/RHSA-2026:14836\", \"tags\": [\"vendor-advisory\", \"x_refsource_REDHAT\"]}, {\"url\": \"https://access.redhat.com/errata/RHSA-2026:13839\", \"tags\": [\"vendor-advisory\", \"x_refsource_REDHAT\"]}, {\"url\": \"https://access.redhat.com/errata/RHSA-2026:15943\", \"tags\": [\"vendor-advisory\", \"x_refsource_REDHAT\"]}, {\"url\": \"https://access.redhat.com/errata/RHSA-2026:15945\", \"tags\": [\"vendor-advisory\", \"x_refsource_REDHAT\"]}, {\"url\": \"https://access.redhat.com/errata/RHSA-2026:13680\", \"tags\": [\"vendor-advisory\", \"x_refsource_REDHAT\"]}, {\"url\": \"https://access.redhat.com/errata/RHSA-2026:15966\", \"tags\": [\"vendor-advisory\", \"x_refsource_REDHAT\"]}, {\"url\": \"https://access.redhat.com/errata/RHSA-2026:6923\", \"tags\": [\"vendor-advisory\", \"x_refsource_REDHAT\"]}, {\"url\": \"https://access.redhat.com/errata/RHSA-2026:7002\", \"tags\": [\"vendor-advisory\", \"x_refsource_REDHAT\"]}, {\"url\": \"https://access.redhat.com/errata/RHSA-2026:7343\", \"tags\": [\"vendor-advisory\", \"x_refsource_REDHAT\"]}, {\"url\": \"https://access.redhat.com/errata/RHSA-2026:8346\", \"tags\": [\"vendor-advisory\", \"x_refsource_REDHAT\"]}, {\"url\": \"https://access.redhat.com/errata/RHSA-2026:10065\", \"tags\": [\"vendor-advisory\", \"x_refsource_REDHAT\"]}], \"workarounds\": [{\"lang\": \"en\", \"value\": \"Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.\"}], \"x_generator\": {\"engine\": \"sadp-cli 1.0.0\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"A flaw was found in NGINX, specifically within the ngx_mail_auth_http_module. When this module is enabled, and CRAM-MD5 or APOP authentication is active with an authentication server that permits retries, undisclosed requests can cause NGINX worker processes to terminate. This can lead to a Denial of Service (DoS), making the affected NGINX instance unavailable to legitimate users.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-476\", \"description\": \"NULL Pointer Dereference\"}]}], \"providerMetadata\": {\"orgId\": \"0b0ca135-0b70-47e7-9f44-1890c2a1c46c\", \"shortName\": \"redhat-SADP\", \"dateUpdated\": \"2026-07-15T01:13:39.490Z\"}}, {\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-27651\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"yes\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-03-24T15:02:03.137056Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-03-24T15:14:09.900Z\"}}], \"cna\": {\"title\": \"NGINX ngx_mail_auth_http_module vulnerability\", \"source\": {\"discovery\": \"EXTERNAL\"}, \"credits\": [{\"lang\": \"en\", \"type\": \"reporter\", \"value\": \"F5 acknowledges Arkadi Vainbrand for bringing this issue to our attention and following the highest standards of coordinated disclosure.\"}], \"metrics\": [{\"format\": \"CVSS\", \"cvssV3_1\": {\"scope\": \"UNCHANGED\", \"version\": \"3.1\", \"baseScore\": 7.5, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"HIGH\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H\", \"integrityImpact\": \"NONE\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"HIGH\", \"privilegesRequired\": \"NONE\", \"confidentialityImpact\": \"NONE\"}, \"scenarios\": [{\"lang\": \"en\", \"value\": \"GENERAL\"}]}, {\"format\": \"CVSS\", \"cvssV4_0\": {\"Safety\": \"NOT_DEFINED\", \"version\": \"4.0\", \"Recovery\": \"NOT_DEFINED\", \"baseScore\": 8.7, \"Automatable\": \"NOT_DEFINED\", \"attackVector\": \"NETWORK\", \"baseSeverity\": \"HIGH\", \"valueDensity\": \"NOT_DEFINED\", \"vectorString\": \"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N\", \"providerUrgency\": \"NOT_DEFINED\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"attackRequirements\": \"NONE\", \"privilegesRequired\": \"NONE\", \"subIntegrityImpact\": \"NONE\", \"vulnIntegrityImpact\": \"NONE\", \"subAvailabilityImpact\": \"NONE\", \"vulnAvailabilityImpact\": \"HIGH\", \"subConfidentialityImpact\": \"NONE\", \"vulnConfidentialityImpact\": \"NONE\", \"vulnerabilityResponseEffort\": \"NOT_DEFINED\"}, \"scenarios\": [{\"lang\": \"en\", \"value\": \"GENERAL\"}]}], \"affected\": [{\"vendor\": \"F5\", \"modules\": [\"ngx_mail_auth_http_module\"], \"product\": \"NGINX Open Source\", \"versions\": [{\"status\": \"affected\", \"version\": \"1.29.0\", \"lessThan\": \"1.29.7\", \"versionType\": \"semver\"}, {\"status\": \"affected\", \"version\": \"0.5.15\", \"lessThan\": \"1.28.3\", \"versionType\": \"semver\"}], \"defaultStatus\": \"unknown\"}, {\"vendor\": \"F5\", \"modules\": [\"ngx_mail_auth_http_module\"], \"product\": \"NGINX Plus\", \"versions\": [{\"status\": \"affected\", \"version\": \"R36\", \"lessThan\": \"R36 P3\", \"versionType\": \"custom\"}, {\"status\": \"affected\", \"version\": \"R35\", \"lessThan\": \"R35 P2\", \"versionType\": \"custom\"}, {\"status\": \"affected\", \"version\": \"R34\", \"lessThan\": \"*\", \"versionType\": \"custom\"}, {\"status\": \"affected\", \"version\": \"R33\", \"lessThan\": \"*\", \"versionType\": \"custom\"}, {\"status\": \"affected\", \"version\": \"R32\", \"lessThan\": \"R32 P5\", \"versionType\": \"custom\"}], \"defaultStatus\": \"unaffected\"}], \"datePublic\": \"2026-03-24T14:00:00.000Z\", \"references\": [{\"url\": \"https://my.f5.com/manage/s/article/K000160383\", \"tags\": [\"vendor-advisory\"]}], \"x_generator\": {\"engine\": \"F5 SIRTBot v1.0\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"When the ngx_mail_auth_http_module\\u00a0module is enabled on NGINX Plus or NGINX Open Source, undisclosed requests can cause worker processes to terminate. This issue may occur when (1) CRAM-MD5 or APOP authentication is enabled, and (2) the authentication server permits retry by returning the Auth-Wait response header. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.\", \"supportingMedia\": [{\"type\": \"text/html\", \"value\": \"\u003cspan style=\\\"background-color: rgb(255, 255, 255);\\\"\u003eWhen the \u003c/span\u003e\u003cstrong\u003engx_mail_auth_http_module\u003c/strong\u003e\u003cspan style=\\\"background-color: rgb(255, 255, 255);\\\"\u003e\u0026nbsp;module is enabled on NGINX Plus or NGINX Open Source, undisclosed requests can cause worker processes to terminate. This issue may occur when (1) CRAM-MD5 or APOP authentication is enabled, and (2) the authentication server permits retry by returning the Auth-Wait response header.\u003c/span\u003e Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.\", \"base64\": false}]}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-476\", \"description\": \"CWE-476 NULL Pointer Dereference\"}]}], \"providerMetadata\": {\"orgId\": \"9dacffd4-cb11-413f-8451-fbbfd4ddc0ab\", \"shortName\": \"f5\", \"dateUpdated\": \"2026-03-24T14:22:35.756Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-27651\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-07-15T01:13:39.490Z\", \"dateReserved\": \"2026-03-18T16:06:38.454Z\", \"assignerOrgId\": \"9dacffd4-cb11-413f-8451-fbbfd4ddc0ab\", \"datePublished\": \"2026-03-24T14:13:27.295Z\", \"assignerShortName\": \"f5\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.