CVE-2026-112906

filelock is a platform-independent file lock for Python. From 4.1.0 until 4.2.1, SoftFileLock versions from 4.1.0 can reuse a stale observation when an attacker pre-dates and removes its own marker, at least two lock-user processes are waiting, coarse or matching modification times preserve the observation, and an honest contender creates a fresh marker on the reused inode, causing that live marker to be removed as stale. This issue is fixed in version 4.2.1.

CVSS 3.1

4.7CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N

EPSS

0.2% chance of exploitation in the next 30 days; higher than 10% of CVEs (scores of 2026-10-25)

CWE

CWE-694

Published

2026-10-20

Modified

2026-10-20

Record from

the NVD, synced 2026-10-21

Packages (OSV)

References

• https://github.com/tox-dev/filelock/commit/740ff666b62a88496c8d7394e4e6230605e4d62b
• https://github.com/tox-dev/filelock/releases/tag/4.2.1
• https://github.com/tox-dev/filelock/security/advisories/GHSA-2g95-wg33-c5x2
• https://github.com/tox-dev/filelock/security/advisories/GHSA-2g95-wg33-c5x2

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