CVE-2026-112939
From 3.22.0 until 4.2.1, SoftFileLock can trust a forged process identifier in a marker that an attacker can modify but cannot remove, allowing an authorized contender such as another process of the holder's account or root to act as a confused deputy,…
Does this matter?
Lower severity and a low EPSS score (0.14%). Track it; it rarely justifies an emergency change on its own.
Description
filelock is a platform-independent file lock for Python. From 3.22.0 until 4.2.1, SoftFileLock can trust a forged process identifier in a marker that an attacker can modify but cannot remove, allowing an authorized contender such as another process of the holder's account or root to act as a confused deputy, remove the live marker, and admit another holder. This issue is fixed in version 4.2.1.
- CVSS 3.1
- 4.7 MEDIUMCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N
- EPSS
- 0.14% probability · 3th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-345
- Affected
- tox-dev/filelock
- Source
- security-advisories@github.com
EPSS moved from 0.1% on 21 October 2026 to 0.1% on 26 October 2026.
References
- https://github.com/tox-dev/filelock/commit/eeceaa846cbe4df72718d94c8371ca1ab8f5b3ccPatch
- https://github.com/tox-dev/filelock/pull/836Patch
- https://github.com/tox-dev/filelock/releases/tag/4.2.1Release Notes
- https://github.com/tox-dev/filelock/security/advisories/GHSA-rfpc-qcw5-3pc4Exploit, Mitigation, Patch, Vendor Advisory
- https://github.com/tox-dev/filelock/security/advisories/GHSA-rfpc-qcw5-3pc4Exploit, Mitigation, Patch, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.