CVE-2026-112939
mediumfilelock is a platform-independent file lock for Python.
Vendor / product: Tox-dev — filelock
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
4.7
4.7 (CVSS v3.1)
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N Severity source: NVD CVSS v3.1 (security-advisories@github.com)
Timeline (UTC)
Published: 2026-10-20 15:17
Modified: 2026-10-21 18:02
NVD status: Analyzed
Last synced 1 day ago
Verified against the source API 2026-10-27 07:04 UTC
Exploitation
Not listed in CISA KEV (as of last catalog sync)
Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).
Affected products
tox-dev / filelock ≥3.22.0 <4.2.1
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
Patch / mitigation: https://github.com/tox-dev/filelock/commit/eeceaa846cbe4df72718d94c8371ca1ab8f5b3cc
Patch / mitigation: https://github.com/tox-dev/filelock/pull/836
Patch / mitigation: https://github.com/tox-dev/filelock/security/advisories/GHSA-rfpc-qcw5-3pc4
Patch / mitigation: https://github.com/tox-dev/filelock/security/advisories/GHSA-rfpc-qcw5-3pc4
References
- https://github.com/tox-dev/filelock/commit/eeceaa846cbe4df72718d94c8371ca1ab8f5b3cc security-advisories@github.com
- https://github.com/tox-dev/filelock/pull/836 security-advisories@github.com
- https://github.com/tox-dev/filelock/releases/tag/4.2.1 security-advisories@github.com
- https://github.com/tox-dev/filelock/security/advisories/GHSA-rfpc-qcw5-3pc4 security-advisories@github.com
- https://github.com/tox-dev/filelock/security/advisories/GHSA-rfpc-qcw5-3pc4 134c704f-9b21-4f2e-91b3-4a467353bcc0
Data sources
NVD CVE API 2.0 — fetched 2026-10-27 07:04 UTC · record ↗