{"id":"CVE-2026-49421","state":"PUBLISHED","title":"unlinkat(2) ignores AT_RESOLVE_BENEATH flag","description":"The kernel function that implements unlinkat(2) and funlinkat(2) validated the AT_RESOLVE_BENEATH flag but failed to pass it through to the underlying path lookup.  The flag was silently dropped, so path resolution was not actually restricted.\n\nA process that uses AT_RESOLVE_BENEATH with unlinkat(2) or funlinkat(2) to confine path resolution can in fact resolve paths above the starting directory.  A caller relying on this flag for path containment may delete files outside the intended directory tree.","publishedAt":"2026-08-19T05:25:43.003Z","updatedAt":"2026-08-26T17:44:13.985Z","severity":{"score":7.1,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H","source":"CISA-ADP"},"assigner":"freebsd","products":["FreeBSD FreeBSD"],"affected":[{"vendor":"FreeBSD","product":"FreeBSD","defaultStatus":"unknown","versions":[{"version":"15.1-RELEASE","status":"affected","lessThan":"p1","versionType":"release"},{"version":"15.0-RELEASE","status":"affected","lessThan":"p11","versionType":"release"},{"version":"14.4-RELEASE","status":"affected","lessThan":"p7","versionType":"release"},{"version":"14.3-RELEASE","status":"affected","lessThan":"p16","versionType":"release"}],"modules":["libalias"]}],"references":["https://security.freebsd.org/advisories/FreeBSD-SA-26:42.unlinkat.asc"],"weaknesses":["CWE-273"],"ingestedAt":"2026-10-29T20:12:07.131Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/49xxx/CVE-2026-49421.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-49421","state":"PUBLISHED","datePublished":"2026-08-19T05:25:43.003Z","dateUpdated":"2026-08-26T17:44:13.985Z","assignerShortName":"freebsd","assignerOrgId":"63664ac6-956c-4cba-a5d0-f46076e16109","dateReserved":"2026-05-29T20:24:28.616Z"},"containers":{"cna":{"title":"unlinkat(2) ignores AT_RESOLVE_BENEATH flag","descriptions":[{"lang":"en","value":"The kernel function that implements unlinkat(2) and funlinkat(2) validated the AT_RESOLVE_BENEATH flag but failed to pass it through to the underlying path lookup.  The flag was silently dropped, so path resolution was not actually restricted.\n\nA process that uses AT_RESOLVE_BENEATH with unlinkat(2) or funlinkat(2) to confine path resolution can in fact resolve paths above the starting directory.  A caller relying on this flag for path containment may delete files outside the intended directory tree."}],"affected":[{"vendor":"FreeBSD","product":"FreeBSD","defaultStatus":"unknown","versions":[{"version":"15.1-RELEASE","status":"affected","lessThan":"p1","versionType":"release"},{"version":"15.0-RELEASE","status":"affected","lessThan":"p11","versionType":"release"},{"version":"14.4-RELEASE","status":"affected","lessThan":"p7","versionType":"release"},{"version":"14.3-RELEASE","status":"affected","lessThan":"p16","versionType":"release"}],"modules":["libalias"]}],"references":[{"url":"https://security.freebsd.org/advisories/FreeBSD-SA-26:42.unlinkat.asc","tags":["vendor-advisory"]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-273","description":"CWE-273: Improper Check for Dropped Privileges","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"freebsd","orgId":"63664ac6-956c-4cba-a5d0-f46076e16109","dateUpdated":"2026-08-19T05:25:43.003Z"},"datePublic":"2026-06-30T20:00:00.000Z","credits":[{"lang":"en","type":"finder","value":"Yuxiang Yang, Yizhou Zhao, Ao Wang, Xuewei Feng, Qi Li, and Ke Xu from Tsinghua University using GLM-5.1 from Z.ai"}],"x_generator":{"engine":"cvelib 1.8.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":7.1,"attackVector":"LOCAL","baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H","integrityImpact":"HIGH","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"HIGH","privilegesRequired":"LOW","confidentialityImpact":"NONE"}},{"other":{"type":"ssvc","content":{"timestamp":"2026-08-26T17:44:11.280156Z","id":"CVE-2026-49421","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-26T17:44:13.985Z"}}]}}}