{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-4266","assignerOrgId":"5d1c2695-1a31-4499-88ae-e847036fd7e3","state":"PUBLISHED","assignerShortName":"WatchGuard","dateReserved":"2026-03-16T12:50:10.806Z","datePublished":"2026-03-30T12:38:01.593Z","dateUpdated":"2026-08-10T16:39:49.547Z"},"containers":{"cna":{"providerMetadata":{"orgId":"5d1c2695-1a31-4499-88ae-e847036fd7e3","shortName":"WatchGuard","dateUpdated":"2026-08-10T16:39:49.547Z"},"title":"WatchGuard Firebox Insecure Deserialization in Fireware Access Portal","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."}],"affected":[{"vendor":"WatchGuard","product":"Fireware OS","versions":[{"status":"affected","version":"2025.1","versionType":"custom","lessThan":"2026.2"},{"status":"affected","version":"12.1","versionType":"custom","lessThan":"12.12"}],"defaultStatus":"unaffected","platforms":["Default"]}],"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"]}],"cpeApplicability":[{"operator":"OR","nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:watchguard:fireware_os:*:*:*:*:*:*:*:*","versionStartIncluding":"2025.1","versionEndExcluding":"2026.2"},{"vulnerable":true,"criteria":"cpe:2.3:a:watchguard:fireware_os:*:*:*:*:*:*:*:*","versionStartIncluding":"12.1","versionEndExcluding":"12.12"}]}]}],"metrics":[{"cvssV4_0":{"version":"4.0","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","baseScore":8.4,"baseSeverity":"HIGH"}}],"problemTypes":[{"descriptions":[{"lang":"en","description":"CWE-502","type":"CWE","cweId":"CWE-502"}]}],"credits":[{"lang":"en","value":"btaol","type":"finder"}],"solutions":[{"lang":"en","value":"Fireware OS 2026.2, Fireware OS 12.12"}],"exploits":[{"lang":"en","value":"WatchGuard is not aware of any exploitation of this issue in the wild."}],"datePublic":"2026-03-30T12:38:01.593Z"},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-03-30T00:00:00+00:00","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3","id":"CVE-2026-4266"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-03-31T03:55:35.825Z"}}]}}