Medium severity · published Oct 20, 2026
CVE-2026-112914
filelock: SoftFileLock stale-break restore follows a swapped-in symbolic link and hard-links a file of the user running the lock into the lock directory
5.3
CVSS
0.2%
EPSS
No
On KEV
Description
filelock is a platform-independent file lock for Python. From 4.1.0 until 4.2.1, SoftFileLock can restore a stale marker by name after moving it aside, allowing another local user with rename access in a non-sticky lock directory to swap in a symbolic link and, on a runtime that follows the link and a same-filesystem target, make the lock user hard-link one of its files into the lock directory. This issue is fixed in version 4.2.1.
CVSS vector
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:N
Attack vector
Local
Complexity
High
Privileges
Low
User interaction
None
Confidentiality
Low
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 5% 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-2026-112914
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-112914
Patch
https://github.com/tox-dev/filelock/commit/740ff666b62a88496c8d7394e4e6230605e4d62b
Patch
https://github.com/tox-dev/filelock/pull/843
Release Notes
https://github.com/tox-dev/filelock/releases/tag/4.2.1
Exploit
https://github.com/tox-dev/filelock/security/advisories/GHSA-crv4-6mhj-j5jh
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6.3
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6.1
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6.1
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