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CVE-2026-22701 Detail

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.


Metrics

NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://github.com/tox-dev/filelock/commit/255ed068bc85d1ef406e50a135e1459170dd1bf0 GitHub, Inc.
https://github.com/tox-dev/filelock/commit/41b42dd2c72aecf7da83dbda5903b8087dddc4d5 GitHub, Inc.
https://github.com/tox-dev/filelock/security/advisories/GHSA-qmgc-5h2g-mvrw GitHub, Inc.

Weakness Enumeration

CWE-ID CWE Name Source
CWE-59 Improper Link Resolution Before File Access ('Link Following') GitHub, Inc.  
CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') GitHub, Inc.  
CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition GitHub, Inc.  

Change History

1 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-22701
NVD Published Date:
01/10/2026
NVD Last Modified:
01/10/2026
Source:
GitHub, Inc.