CVE-2026-49421
Description
AI Translation Available
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.
A 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.
273
Improper Check for Dropped Privileges
IncompleteCommon Consequences
Security Scopes Affected:
Access Control
Non-Repudiation
Potential Impacts:
Gain Privileges Or Assume Identity
Hide Activities
Applicable Platforms
All platforms may be affected
https://security.freebsd.org/advisories/FreeBSD-SA-26:42.unlinkat.asc