Low severity · published Oct 20, 2026
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
3.3
CVSS
0.1%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
None
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.1% · higher than 3% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FI
filelock · tox-dev
>= 4.1.0, < 4.2.1 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-112941
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-112941
Patch
https://github.com/tox-dev/filelock/commit/bfa066d65a1ba9106f86ee9d027f7588b9c77e03
Patch
https://github.com/tox-dev/filelock/pull/842
Release Notes
https://github.com/tox-dev/filelock/releases/tag/4.2.1
Exploit
https://github.com/tox-dev/filelock/security/advisories/GHSA-wfhq-q4j2-c37m
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