CVE-2026-112941

filelock: SoftReadWriteLock follows a lock tree swapped in after its first acquire and writes lock records into directories of the user running the lock

Published Oct 20, 2026 CVSS 3.1 · 3.3 Low EPSS < 1% KEV · Not listed
Description
filelock is a platform-independent file lock for Python. From 4.1.0 until 4.2.1, SoftReadWriteLock and AsyncSoftReadWriteLock cache a successful check of the <path>.rw lock tree and resolve its names again during later record operations, allowing another local user who can replace that tree after the first acquisition to redirect lock-record writes into directories writable by the lock user. This issue is fixed in version 4.2.1.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-wfhq-q4j2-c37m filelock: SoftReadWriteLock follows a lock tree swapped in after its first acquire and writes lock records into directories of the user running the lock
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
CPEs cpe:2.3:a:tox-dev:filelock:*:*:*:*:*:python:*:*
Type Values Removed Values Added
First Time appeared Tox-dev
Tox-dev filelock
Vendors & Products Tox-dev
Tox-dev filelock
Type Values Removed Values Added
Description filelock is a platform-independent file lock for Python. From 4.1.0 until 4.2.1, SoftReadWriteLock and AsyncSoftReadWriteLock cache a successful check of the <path>.rw lock tree and resolve its names again during later record operations, allowing another local user who can replace that tree after the first acquisition to redirect lock-record writes into directories writable by the lock user. This issue is fixed in version 4.2.1.
Title filelock: SoftReadWriteLock follows a lock tree swapped in after its first acquire and writes lock records into directories of the user running the lock
Weaknesses CWE-367
References
Metrics cvssV3_1

{'score': 3.3, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Oct 28, 2026, 2:14 PM
Reserved
Oct 19, 2026, 9:30 PM
Status
Modified
Published
Oct 20, 2026, 3:17 PM
Modified
Oct 28, 2026, 3:17 PM
Severity
Low
Public date
Oct 20, 2026, 2:43 PM