filelock: SoftFileLock removes a live holder's marker when another user forges the PID in a writable marker

影響: pip:filelock >= 3.22.0, <= 4.2.0 → 4.2.1

SoftFileLock, MarkerSoftFileLock, SoftFileLease, their async variants and a FileLock that has fallen back to a soft lock on ENOSYS decide from the record inside the marker file whether its owner is gone. The marker is the file whose presence says a process holds the lock. They do not check who could have written that record. A local user who can write the marker but cannot remove it rewrites the holder's record to name a dead PID (process id). That position arises with an explicit mode with gro…

Read on GitHub Advisory Database

On 10/29/2026, 06:08 AM, GitHub Advisory Database published "filelock: SoftFileLock removes a live holder's marker when another user forges the PID in a writable marker" (type: Advisory). Severity is "Medium" (medium). Related technologies: Python. CVE: CVE-2026-112939.