CVE-2026-112912 — filelock: Symlink swap during SoftFileLock's writability check leaks whether a path exists and is writable by the lock taker
filelock is a platform-independent file lock for Python. From 3.32.6 until 4.2.1, SoftFileLock can follow a swapped symbolic link during the conditional os.access writability ch…
Published: 2026-10-20 · CVSS: 2.5 · CVSS 3.1
filelock is a platform-independent file lock for Python. From 3.32.6 until 4.2.1, SoftFileLock can follow a swapped symbolic link during the conditional os.access writability check for a node without its owner-write bit, allowing another local user on a platform and directory configuration that follows the link to infer whether a chosen path exists and is writable from the observable acquisition result. This issue is fixed in version 4.2.1.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7