CVE-2026-4266 (GCVE-0-2026-4266)
Vulnerability from cvelistv5
Published
2026-03-30 12:38
Modified
2026-08-27 22:58
Severity ?
8.4 (High) - CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CWE
Summary
An Insecure Deserialization vulnerability in WatchGuard Fireware OS allows an attacker that has obtained write access to the local filesystem through another vulnerability to execute arbitrary code in the context of the portald user. Note, this vulnerability does not affect Firebox platforms that do not support the Access Portal feature, including the T15 and T35.
References
Impacted products
Vendor Product Version
WatchGuard Fireware OS Version: 2025.1   < 2026.2
Version: 12.1   < 12.12
 Create a notification for this product.
Show details on NVD website

To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-4266",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-03-30T00:00:00+00:00",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-03-31T03:55:35.825Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "platforms": [
            "Default"
          ],
          "product": "Fireware OS",
          "vendor": "WatchGuard",
          "versions": [
            {
              "lessThan": "2026.2",
              "status": "affected",
              "version": "2025.1",
              "versionType": "custom"
            },
            {
              "lessThan": "12.12",
              "status": "affected",
              "version": "12.1",
              "versionType": "custom"
            }
          ]
        },
        {
          "defaultStatus": "unaffected",
          "platforms": [
            "EUCC"
          ],
          "product": "Fireware OS",
          "vendor": "WatchGuard",
          "versions": [
            {
              "lessThan": "12.11.9",
              "status": "affected",
              "version": "12.1",
              "versionType": "custom"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:a:watchguard:fireware_os:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "2026.2",
                  "versionStartIncluding": "2025.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:a:watchguard:fireware_os:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "12.12",
                  "versionStartIncluding": "12.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:a:watchguard:fireware_os:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "12.11.9",
                  "versionStartIncluding": "12.1",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ],
          "operator": "OR"
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "btaol"
        }
      ],
      "datePublic": "2026-03-30T12:38:01.593Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "An Insecure Deserialization vulnerability in WatchGuard Fireware OS allows an attacker that has obtained write access to the local filesystem through another vulnerability to execute arbitrary code in the context of the portald user.\n\nNote, this vulnerability does not affect Firebox platforms that do not support the Access Portal feature, including the T15 and T35."
        }
      ],
      "exploits": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "WatchGuard is not aware of any exploitation of this issue in the wild."
            }
          ],
          "value": "WatchGuard is not aware of any exploitation of this issue in the wild."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "baseScore": 8.4,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
            "version": "4.0"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-502",
              "description": "CWE-502",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-27T22:58:27.131Z",
        "orgId": "5d1c2695-1a31-4499-88ae-e847036fd7e3",
        "shortName": "WatchGuard"
      },
      "references": [
        {
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://psirt.watchguard.com/CVE-2026-4266"
        },
        {
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://www.watchguard.com/wgrd-psirt/advisory/wgsa-2026-00007"
        }
      ],
      "solutions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "Fireware OS 2026.2, Fireware OS 12.12, Fireware OS 12.11.9"
            }
          ],
          "value": "Fireware OS 2026.2, Fireware OS 12.12, Fireware OS 12.11.9"
        }
      ],
      "title": "WatchGuard Firebox Insecure Deserialization in Fireware Access Portal"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "5d1c2695-1a31-4499-88ae-e847036fd7e3",
    "assignerShortName": "WatchGuard",
    "cveId": "CVE-2026-4266",
    "datePublished": "2026-03-30T12:38:01.593Z",
    "dateReserved": "2026-03-16T12:50:10.806Z",
    "dateUpdated": "2026-08-27T22:58:27.131Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-4266\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"total\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-03-30T13:19:48.660512Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-03-30T13:19:52.252Z\"}}], \"cna\": {\"title\": \"WatchGuard Firebox Insecure Deserialization in Fireware Access Portal\", \"credits\": [{\"lang\": \"en\", \"type\": \"finder\", \"value\": \"btaol\"}], \"metrics\": [{\"cvssV4_0\": {\"version\": \"4.0\", \"baseScore\": 8.4, \"baseSeverity\": \"HIGH\", \"vectorString\": \"CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N\"}}], \"affected\": [{\"vendor\": \"WatchGuard\", \"product\": \"Fireware OS\", \"versions\": [{\"status\": \"affected\", \"version\": \"2025.1\", \"lessThan\": \"2026.2\", \"versionType\": \"custom\"}, {\"status\": \"affected\", \"version\": \"12.1\", \"lessThan\": \"12.12\", \"versionType\": \"custom\"}], \"platforms\": [\"Default\"], \"defaultStatus\": \"unaffected\"}, {\"vendor\": \"WatchGuard\", \"product\": \"Fireware OS\", \"versions\": [{\"status\": \"affected\", \"version\": \"12.1\", \"lessThan\": \"12.11.9\", \"versionType\": \"custom\"}], \"platforms\": [\"EUCC\"], \"defaultStatus\": \"unaffected\"}], \"exploits\": [{\"lang\": \"en\", \"value\": \"WatchGuard is not aware of any exploitation of this issue in the wild.\", \"supportingMedia\": [{\"type\": \"text/html\", \"value\": \"WatchGuard is not aware of any exploitation of this issue in the wild.\", \"base64\": false}]}], \"solutions\": [{\"lang\": \"en\", \"value\": \"Fireware OS 2026.2, Fireware OS 12.12, Fireware OS 12.11.9\", \"supportingMedia\": [{\"type\": \"text/html\", \"value\": \"Fireware OS 2026.2, Fireware OS 12.12, Fireware OS 12.11.9\", \"base64\": false}]}], \"datePublic\": \"2026-03-30T12:38:01.593Z\", \"references\": [{\"url\": \"https://psirt.watchguard.com/CVE-2026-4266\", \"tags\": [\"vendor-advisory\"]}, {\"url\": \"https://www.watchguard.com/wgrd-psirt/advisory/wgsa-2026-00007\", \"tags\": [\"vendor-advisory\"]}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"An Insecure Deserialization vulnerability in WatchGuard Fireware OS allows an attacker that has obtained write access to the local filesystem through another vulnerability to execute arbitrary code in the context of the portald user.\\n\\nNote, this vulnerability does not affect Firebox platforms that do not support the Access Portal feature, including the T15 and T35.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-502\", \"description\": \"CWE-502\"}]}], \"cpeApplicability\": [{\"nodes\": [{\"negate\": false, \"cpeMatch\": [{\"criteria\": \"cpe:2.3:a:watchguard:fireware_os:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"2026.2\", \"versionStartIncluding\": \"2025.1\"}, {\"criteria\": \"cpe:2.3:a:watchguard:fireware_os:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"12.12\", \"versionStartIncluding\": \"12.1\"}, {\"criteria\": \"cpe:2.3:a:watchguard:fireware_os:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"12.11.9\", \"versionStartIncluding\": \"12.1\"}], \"operator\": \"OR\"}], \"operator\": \"OR\"}], \"providerMetadata\": {\"orgId\": \"5d1c2695-1a31-4499-88ae-e847036fd7e3\", \"shortName\": \"WatchGuard\", \"dateUpdated\": \"2026-08-27T22:58:27.131Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-4266\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-08-27T22:58:27.131Z\", \"dateReserved\": \"2026-03-16T12:50:10.806Z\", \"assignerOrgId\": \"5d1c2695-1a31-4499-88ae-e847036fd7e3\", \"datePublished\": \"2026-03-30T12:38:01.593Z\", \"assignerShortName\": \"WatchGuard\"}",
      "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.