{"api_version":"1","generated_at":"2026-08-19T11:45:16+00:00","cve":"CVE-2026-49421","urls":{"html":"https://cve.report/CVE-2026-49421","api":"https://cve.report/api/cve/CVE-2026-49421.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-49421","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-49421"},"summary":{"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.","state":"PUBLISHED","assigner":"freebsd","published_at":"2026-08-19 06:17:41","updated_at":"2026-08-19 06:17:41"},"problem_types":["CWE-273","CWE-273 CWE-273: Improper Check for Dropped Privileges"],"metrics":[],"references":[{"url":"https://security.freebsd.org/advisories/FreeBSD-SA-26:42.unlinkat.asc","name":"https://security.freebsd.org/advisories/FreeBSD-SA-26:42.unlinkat.asc","refsource":"secteam@freebsd.org","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-49421","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-49421","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"FreeBSD","product":"FreeBSD","version":"affected 15.1-RELEASE p1 release","platforms":[]},{"source":"CNA","vendor":"FreeBSD","product":"FreeBSD","version":"affected 15.0-RELEASE p11 release","platforms":[]},{"source":"CNA","vendor":"FreeBSD","product":"FreeBSD","version":"affected 14.4-RELEASE p7 release","platforms":[]},{"source":"CNA","vendor":"FreeBSD","product":"FreeBSD","version":"affected 14.3-RELEASE p16 release","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[{"source":"CNA","value":"Yuxiang Yang, Yizhou Zhao, Ao Wang, Xuewei Feng, Qi Li, and Ke Xu from Tsinghua University using GLM-5.1 from Z.ai","lang":"en"}],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unknown","modules":["libalias"],"product":"FreeBSD","vendor":"FreeBSD","versions":[{"lessThan":"p1","status":"affected","version":"15.1-RELEASE","versionType":"release"},{"lessThan":"p11","status":"affected","version":"15.0-RELEASE","versionType":"release"},{"lessThan":"p7","status":"affected","version":"14.4-RELEASE","versionType":"release"},{"lessThan":"p16","status":"affected","version":"14.3-RELEASE","versionType":"release"}]}],"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"}],"datePublic":"2026-06-30T20:00:00.000Z","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."}],"problemTypes":[{"descriptions":[{"cweId":"CWE-273","description":"CWE-273: Improper Check for Dropped Privileges","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-08-19T05:25:43.003Z","orgId":"63664ac6-956c-4cba-a5d0-f46076e16109","shortName":"freebsd"},"references":[{"tags":["vendor-advisory"],"url":"https://security.freebsd.org/advisories/FreeBSD-SA-26:42.unlinkat.asc"}],"title":"unlinkat(2) ignores AT_RESOLVE_BENEATH flag","x_generator":{"engine":"cvelib 1.8.0"}}},"cveMetadata":{"assignerOrgId":"63664ac6-956c-4cba-a5d0-f46076e16109","assignerShortName":"freebsd","cveId":"CVE-2026-49421","datePublished":"2026-08-19T05:25:43.003Z","dateReserved":"2026-05-29T20:24:28.616Z","dateUpdated":"2026-08-19T05:25:43.003Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-19 06:17:41","lastModifiedDate":"2026-08-19 06:17:41","problem_types":["CWE-273","CWE-273 CWE-273: Improper Check for Dropped Privileges"],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"49421","Ordinal":"1","Title":"unlinkat(2) ignores AT_RESOLVE_BENEATH flag","CVE":"CVE-2026-49421","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"49421","Ordinal":"1","NoteData":"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.","Type":"Description","Title":"unlinkat(2) ignores AT_RESOLVE_BENEATH flag"}]}}}