CVE-2026-112938

Publication date 6 November 2026

Last updated 6 November 2026

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

5.8 · Medium

Score breakdown

Description

filelock is a platform-independent file lock for Python. From 3.30.0 until 4.2.1, On POSIX platforms, StrictSoftFileLock and AsyncStrictSoftFileLock validate the coordination directory in _ensure_protocol_directory but later reach the claims directory through _open_directory by pathname, allowing a local account that can rename the coordination name to swap in a symbolic link between check and use during acquisition. That race can create and leave claim files in another writable directory or strand claims in a different strict lock so the second lock times out. Separately, the claims property and force_break follow a resting symbolic link without a race when the lock user inspects or recovers the lock. Claims inspection discloses a file name to the other account only if the resulting exception text or claim_name reaches that account through a shared log, CI output, or error report. A blind force_break recovery that removes live claims from another strict lock can allow two processes into that lock's critical section; this path reaches other strict locks, not arbitrary files. This issue is fixed in version 4.2.1.

Status

Package Ubuntu Release Status
python-filelock 26.10 stonking
Needs evaluation
26.04 LTS resolute
Needs evaluation
24.04 LTS noble
Needs evaluation
22.04 LTS jammy
Needs evaluation
20.04 LTS focal
Needs evaluation
18.04 LTS bionic
Needs evaluation

Severity score breakdown

CVSS version: CVSS v3.0

Base score 5.8 · Medium

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

References

Other references

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