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

- 種別: advisory
- 重大度: medium
- 関連技術: python
- CVE: CVE-2026-112939
- 公開日時: 2026-10-28T21:08:45.000Z
- 情報源: GitHub Advisory Database (https://github.com/advisories/GHSA-rfpc-qcw5-3pc4)
- パーマリンク: https://vulnpulse.app/items/ghsa-ghsa-rfpc-qcw5-3pc4

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…