Time-of-check Time-of-use (TOCTOU) Affecting python-filelock-doc package, versions <0:3.3.1-1.amzn2023.0.2


Severity

Recommended
0.0
medium
0
10

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.02% (5th percentile)

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  • Snyk IDSNYK-AMZN2023-PYTHONFILELOCKDOC-15245544
  • published6 Feb 2026
  • disclosed10 Jan 2026

Introduced: 10 Jan 2026

CVE-2026-22701  (opens in a new tab)
CWE-367  (opens in a new tab)

How to fix?

Upgrade Amazon-Linux:2023 python-filelock-doc to version 0:3.3.1-1.amzn2023.0.2 or higher.
This issue was patched in ALAS2023-2026-1415.

NVD Description

Note: Versions mentioned in the description apply only to the upstream python-filelock-doc package and not the python-filelock-doc package as distributed by Amazon-Linux. See How to fix? for Amazon-Linux:2023 relevant fixed versions and status.

filelock is a platform-independent file lock for Python. Prior to version 3.20.3, a TOCTOU race condition vulnerability exists in the SoftFileLock implementation of the filelock package. An attacker with local filesystem access and permission to create symlinks can exploit a race condition between the permission validation and file creation to cause lock operations to fail or behave unexpectedly. The vulnerability occurs in the _acquire() method between raise_on_not_writable_file() (permission check) and os.open() (file creation). During this race window, an attacker can create a symlink at the lock file path, potentially causing the lock to operate on an unintended target file or leading to denial of service. This issue has been patched in version 3.20.3.

CVSS Base Scores

version 3.1