{"id":"CVE-2026-121520","aliases":["AZL-112726","AZL-112729","AZL-112756","EUVD-2026-116538","GHSA-w26x-xg27-7qjc","UBUNTU-CVE-2026-121520"],"status":"published","title":"Malicious client could set xattr value outside of BuildKit state directory","description":"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.","severity":{"version":"4.0","score":4.5,"vector":"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","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00139,"percentile":0.03302,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-61"],"published":"2026-11-03T22:11:57Z","modified":"2026-11-07T14:19:16Z","affected":[{"source":"osv","ecosystem":"Azure Linux:3","package":"docker-buildx","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"0.14.0-19"}]}]},{"source":"osv","ecosystem":"Azure Linux:3","package":"docker-compose","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"2.27.0-16"}]}]},{"source":"osv","ecosystem":"Azure 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:26.04:LTS","package":"docker.io","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["26.1.5+dfsg1-9ubuntu1","27.5.1+dfsg4-1ubuntu1","27.5.1+dfsg4-2ubuntu1"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"docker.io-app","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["28.2.2-0ubuntu1","29.1.2-0ubuntu1","29.1.3-0ubuntu1","29.1.3-0ubuntu2","29.1.3-0ubuntu3","29.1.3-0ubuntu4","29.1.3-0ubuntu4.1"]}],"products":[{"vendor":"moby","product":"buildkit"}],"references":[{"url":"https://github.com/moby/buildkit/security/advisories/GHSA-w26x-xg27-7qjc","tags":["vendor-advisory","advisory","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-121520","tags":["web","advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/121xxx/CVE-2026-121520.json","tags":["advisory"]},{"url":"https://github.com/moby/buildkit","tags":["package"]},{"url":"https://ubuntu.com/security/CVE-2026-121520","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-121520","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-121520","title":"Malicious client could set xattr value outside of BuildKit state directory","description":"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.","status":"published","published":"2026-11-03T22:11:57.202Z","modified":"2026-11-06T19:31:00.151Z","cvss":[{"version":"4.0","score":4.5,"vector":"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","level":"medium","assessor":"cna"}],"cwes":["CWE-61"],"updated_at":"2026-11-06T20:30:04.265548Z"}],"euvd":[{"id":"EUVD-2026-116538","description":"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.","status":"published","published":"2026-11-03T22:11:57Z","modified":"2026-11-06T19:31:00Z","cvss":[{"version":"4.0","score":4.5,"vector":"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","level":"medium"}],"updated_at":"2026-11-06T20:06:05.048214Z"}],"nvd":[{"id":"CVE-2026-121520","description":"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.","status":"published","published":"2026-11-03T23:17:34.177Z","modified":"2026-11-06T21:40:43.45Z","cvss":[{"version":"4.0","score":4.5,"vector":"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium","assessor":"secondary"}],"cwes":["CWE-61"],"updated_at":"2026-11-06T22:02:16.475328Z"}],"osv":[{"id":"CVE-2026-121520","title":"Malicious client could set xattr value outside of BuildKit state directory","description":"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.","status":"published","published":"2026-11-03T22:11:57.202Z","modified":"2026-11-08T02:30:16.739467709Z","cvss":[{"version":"4.0","score":4.5,"vector":"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","level":"medium"}],"cwes":["CWE-61"],"updated_at":"2026-11-07T11:15:41.683306Z"},{"id":"UBUNTU-CVE-2026-121520","description":"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.","status":"published","published":"2026-11-03T23:17:00Z","modified":"2026-11-05T11:45:27.660582757Z","cvss":[{"version":"4.0","score":4.5,"vector":"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","level":"medium"}],"updated_at":"2026-11-05T13:30:49.23793Z"},{"id":"AZL-112726","title":"CVE-2026-121520 affecting package docker-buildx 0.14.0-19","description":"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.","status":"published","published":"2026-11-03T23:17:34Z","modified":"2026-11-07T14:19:16.205924241Z","updated_at":"2026-11-07T14:48:11.583685Z"},{"id":"AZL-112729","title":"CVE-2026-121520 affecting package docker-compose 2.27.0-16","description":"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.","status":"published","published":"2026-11-03T23:17:34Z","modified":"2026-11-07T14:18:07.243622215Z","updated_at":"2026-11-07T14:48:11.583685Z"},{"id":"AZL-112756","title":"CVE-2026-121520 affecting package moby-engine 25.0.18-1","description":"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.","status":"published","published":"2026-11-03T23:17:34Z","modified":"2026-11-07T14:18:05.076869672Z","updated_at":"2026-11-07T14:48:11.583685Z"}]}}