CVE-2026-4438 (GCVE-0-2026-4438)
Vulnerability from cvelistv5
Published
2026-03-20 19:59
Modified
2026-03-23 15:06
Severity ?
5.4 (Medium) - CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
CWE
  • CWE-20 - Improper input validation
Summary
Calling gethostbyaddr or gethostbyaddr_r with a configured nsswitch.conf that specifies the library's DNS backend in the GNU C library version 2.34 to version 2.43 could result in an invalid DNS hostname being returned to the caller in violation of the DNS specification.
References
Impacted products
Vendor Product Version
The GNU C Library glibc Version: 2.34   <
Create a notification for this product.
Show details on NVD website

To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "ADJACENT_NETWORK",
              "availabilityImpact": "NONE",
              "baseScore": 5.4,
              "baseSeverity": "MEDIUM",
              "confidentialityImpact": "LOW",
              "integrityImpact": "LOW",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-4438",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-03-23T15:06:13.636418Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-88",
                "description": "CWE-88 Improper Neutralization of Argument Delimiters in a Command (\u0027Argument Injection\u0027)",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-03-23T15:06:16.376Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "glibc",
          "vendor": "The GNU C Library",
          "versions": [
            {
              "lessThanOrEqual": "2.43",
              "status": "affected",
              "version": "2.34",
              "versionType": "custom"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Antonio Maini (0rbitingZer0) - 0rbitingZer0@proton.me"
        }
      ],
      "datePublic": "2026-03-20T22:17:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "\u003cdiv\u003eCalling gethostbyaddr or gethostbyaddr_r with a configured nsswitch.conf that specifies the library\u0027s DNS backend in the GNU C library version 2.34 to version 2.43 could result in an invalid DNS hostname being returned to the caller in violation of the DNS specification.\u003c/div\u003e"
            }
          ],
          "value": "Calling gethostbyaddr or gethostbyaddr_r with a configured nsswitch.conf that specifies the library\u0027s DNS backend in the GNU C library version 2.34 to version 2.43 could result in an invalid DNS hostname being returned to the caller in violation of the DNS specification."
        }
      ],
      "impacts": [
        {
          "capecId": "CAPEC-142",
          "descriptions": [
            {
              "lang": "en",
              "value": "CAPEC-142 DNS Cache Poisoning"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-20",
              "description": "CWE-20 Improper input validation",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-03-20T19:59:06.064Z",
        "orgId": "3ff69d7a-14f2-4f67-a097-88dee7810d18",
        "shortName": "glibc"
      },
      "references": [
        {
          "url": "https://sourceware.org/bugzilla/show_bug.cgi?id=34015"
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "title": "gethostbyaddr and gethostbyaddr_r return invalid DNS hostnames",
      "x_generator": {
        "engine": "Vulnogram 1.0.1"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "3ff69d7a-14f2-4f67-a097-88dee7810d18",
    "assignerShortName": "glibc",
    "cveId": "CVE-2026-4438",
    "datePublished": "2026-03-20T19:59:06.064Z",
    "dateReserved": "2026-03-19T19:55:44.639Z",
    "dateUpdated": "2026-03-23T15:06:16.376Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "vulnrichment": {
      "containers": "{\"cna\": {\"providerMetadata\": {\"orgId\": \"3ff69d7a-14f2-4f67-a097-88dee7810d18\", \"shortName\": \"glibc\", \"dateUpdated\": \"2026-03-20T19:59:06.064Z\"}, \"title\": \"gethostbyaddr and gethostbyaddr_r return invalid DNS hostnames\", \"datePublic\": \"2026-03-20T22:17:00.000Z\", \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"cweId\": \"CWE-20\", \"description\": \"CWE-20 Improper input validation\", \"type\": \"CWE\"}]}], \"impacts\": [{\"capecId\": \"CAPEC-142\", \"descriptions\": [{\"lang\": \"en\", \"value\": \"CAPEC-142 DNS Cache Poisoning\"}]}], \"affected\": [{\"vendor\": \"The GNU C Library\", \"product\": \"glibc\", \"versions\": [{\"status\": \"affected\", \"version\": \"2.34\", \"lessThanOrEqual\": \"2.43\", \"versionType\": \"custom\"}], \"defaultStatus\": \"unaffected\"}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"Calling gethostbyaddr or gethostbyaddr_r with a configured nsswitch.conf that specifies the library\u0027s DNS backend in the GNU C library version 2.34 to version 2.43 could result in an invalid DNS hostname being returned to the caller in violation of the DNS specification.\", \"supportingMedia\": [{\"type\": \"text/html\", \"base64\": false, \"value\": \"\u003cdiv\u003eCalling gethostbyaddr or gethostbyaddr_r with a configured nsswitch.conf that specifies the library\u0027s DNS backend in the GNU C library version 2.34 to version 2.43 could result in an invalid DNS hostname being returned to the caller in violation of the DNS specification.\u003c/div\u003e\"}]}], \"references\": [{\"url\": \"https://sourceware.org/bugzilla/show_bug.cgi?id=34015\"}], \"credits\": [{\"lang\": \"en\", \"value\": \"Antonio Maini (0rbitingZer0) - 0rbitingZer0@proton.me\", \"type\": \"finder\"}], \"source\": {\"discovery\": \"UNKNOWN\"}, \"x_generator\": {\"engine\": \"Vulnogram 1.0.1\"}}, \"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"cvssV3_1\": {\"scope\": \"UNCHANGED\", \"version\": \"3.1\", \"baseScore\": 5.4, \"attackVector\": \"ADJACENT_NETWORK\", \"baseSeverity\": \"MEDIUM\", \"vectorString\": \"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N\", \"integrityImpact\": \"LOW\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"NONE\", \"privilegesRequired\": \"NONE\", \"confidentialityImpact\": \"LOW\"}}, {\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-4438\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-03-23T15:06:13.636418Z\"}}}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-88\", \"description\": \"CWE-88 Improper Neutralization of Argument Delimiters in a Command (\u0027Argument Injection\u0027)\"}]}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-03-23T15:06:06.683Z\"}}]}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-4438\", \"assignerOrgId\": \"3ff69d7a-14f2-4f67-a097-88dee7810d18\", \"state\": \"PUBLISHED\", \"assignerShortName\": \"glibc\", \"dateReserved\": \"2026-03-19T19:55:44.639Z\", \"datePublished\": \"2026-03-20T19:59:06.064Z\", \"dateUpdated\": \"2026-03-23T15:06:16.376Z\"}",
      "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.