filelock: SoftReadWriteLock holder refresh writes through a hard link and hangs on a named pipe that another local user renames over its record

影響: pip:filelock >= 4.0.0, <= 4.2.0 → 4.2.1

SoftReadWriteLock (and AsyncSoftReadWriteLock, which wraps one) refreshes its holder record (the file under .rw/holders/ that says a process holds or wants the lock) on every poll of a waiting acquire and on every heartbeat (the periodic refresh a holder runs to keep its record fresh). It does so by reopening .rw/holders/ by name with a plain blocking O_WRONLY | O_NOFOLLOW open and writing at offset 0, without checking what it opened. O_NOFOLLOW makes the open fail only when the final name is a…

Read on GitHub Advisory Database

On 10/29/2026, 06:08 AM, GitHub Advisory Database published "filelock: SoftReadWriteLock holder refresh writes through a hard link and hangs on a named pipe that another local user renames over its record" (type: Advisory). Severity is "Medium" (medium). Related technologies: Python. CVE: CVE-2026-112934.