CVE-2026-22701

Published Jan 10, 2026

Last updated 6 months ago

CVSS medium 5.3
Supply chain

Overview

Description
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.
Source
security-advisories@github.com
NVD status
Analyzed
Products
filelock

Risk scores

CVSS 3.1

Type
Secondary
Base score
5.3
Impact score
4.2
Exploitability score
1
Vector string
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:H
Severity
MEDIUM

Weaknesses

security-advisories@github.com
CWE-59

Social media

Hype score
Not currently trending

Configurations