{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-121520","assignerOrgId":"686469e6-3ff6-451b-ab8b-cf5b9e89401e","state":"PUBLISHED","assignerShortName":"Docker","dateReserved":"2026-11-03T14:26:45.909Z","datePublished":"2026-11-03T22:11:57.202Z","dateUpdated":"2026-11-06T19:31:00.151Z"},"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"BuildKit","vendor":"Moby","repo":"https://github.com/moby/buildkit","versions":[{"version":"0","status":"affected","lessThan":"0.34.1","versionType":"semver"}]}],"descriptions":[{"lang":"en","value":"In BuildKit versions prior to v0.34.1, a malicious client with access to the BuildKit control APIs can submit a build request that sets an extended attribute on a file outside the BuildKit state directory. Extended attributes in the trusted. or security. namespaces may also be set, potentially giving a program on the host elevated privileges. This issue affects build services that accept build requests from untrusted users. The issue is fixed in v0.34.1."}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"Host security-label modification"}],"cvssV4_0":{"version":"4.0","vectorString":"CVSS:4.0/AV:L/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:N/SC:N/SI:H/SA:H","baseScore":4.5,"baseSeverity":"MEDIUM"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-61","description":"CWE-61: UNIX Symbolic Link (Symlink) Following","lang":"en","type":"CWE"}]}],"providerMetadata":{"orgId":"686469e6-3ff6-451b-ab8b-cf5b9e89401e","shortName":"Docker","dateUpdated":"2026-11-03T22:11:57.202Z"},"references":[{"tags":["vendor-advisory"],"url":"https://github.com/moby/buildkit/security/advisories/GHSA-w26x-xg27-7qjc"}],"source":{"discovery":"EXTERNAL"},"title":"Malicious client could set xattr value outside of BuildKit state directory","solutions":[{"lang":"en","value":"Upgrade BuildKit to v0.34.1 or later."}],"workarounds":[{"lang":"en","value":"Restrict access to BuildKit control APIs to trusted clients and do not accept build requests from untrusted users."}]},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-11-06T19:30:46.298631Z","id":"CVE-2026-121520","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-11-06T19:31:00.151Z"}}]}}