CVE-2026-112940
filelock ReadWriteLock: SQLite reopens the lock database by name, so a planted symlink or journal file makes the lock user's process overwrite or unlink its own files
Description
filelock is a platform-independent file lock for Python. From 3.20.4 until 4.2.1, ReadWriteLock let SQLite reopen the database and side files by name; on POSIX systems an attacker with rename access in a non-sticky parent can swap those names to cause overwrite or unlink operations, while a writable adjacent hot journal is additionally required for attacker-chosen content overwrites. This issue is fixed in version 4.2.1.
INFO
Published Date :
Oct. 20, 2026, 3:17 p.m.
Last Modified :
Oct. 22, 2026, 10:18 p.m.
Remotely Exploit :
No
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | MITRE-CVE | ||||
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Update filelock to version 4.2.1.
- Ensure proper file permissions.
- Review file system configurations.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-112940.
| URL | Resource |
|---|---|
| https://github.com/tox-dev/filelock/commit/5e3f2ec0c5fb17cb2635b60b2b68bc63ab81ca2d | Patch |
| https://github.com/tox-dev/filelock/pull/834 | Patch |
| https://github.com/tox-dev/filelock/releases/tag/4.2.1 | Release Notes |
| https://github.com/tox-dev/filelock/security/advisories/GHSA-v4x8-3wr5-3wq8 | Exploit Mitigation Patch Vendor Advisory |
| https://github.com/tox-dev/filelock/security/advisories/GHSA-v4x8-3wr5-3wq8 | Exploit Mitigation Patch Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-112940 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-112940
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-112940 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-112940 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Oct. 22, 2026
Action Type Old Value New Value Added Reference https://github.com/tox-dev/filelock/security/advisories/GHSA-v4x8-3wr5-3wq8 Added SSVC {'id': 'CVE-2026-112940', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-10-22T21:29:06.989000Z'} -
Initial Analysis by [email protected]
Oct. 21, 2026
Action Type Old Value New Value Added CWE CWE-59 Added CPE Configuration OR *cpe:2.3:a:tox-dev:filelock:*:*:*:*:*:python:*:* versions from (including) 3.20.4 up to (excluding) 4.2.1 Added Reference Type GitHub, Inc.: https://github.com/tox-dev/filelock/commit/5e3f2ec0c5fb17cb2635b60b2b68bc63ab81ca2d Types: Patch Added Reference Type GitHub, Inc.: https://github.com/tox-dev/filelock/pull/834 Types: Patch Added Reference Type GitHub, Inc.: https://github.com/tox-dev/filelock/releases/tag/4.2.1 Types: Release Notes Added Reference Type GitHub, Inc.: https://github.com/tox-dev/filelock/security/advisories/GHSA-v4x8-3wr5-3wq8 Types: Exploit, Mitigation, Patch, Vendor Advisory -
New CVE Received by [email protected]
Oct. 20, 2026
Action Type Old Value New Value Added Description filelock is a platform-independent file lock for Python. From 3.20.4 until 4.2.1, ReadWriteLock let SQLite reopen the database and side files by name; on POSIX systems an attacker with rename access in a non-sticky parent can swap those names to cause overwrite or unlink operations, while a writable adjacent hot journal is additionally required for attacker-chosen content overwrites. This issue is fixed in version 4.2.1. Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H Added CWE CWE-363 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/112xxx/CVE-2026-112940.json">CVE-2026-112940</a> Added Reference https://github.com/tox-dev/filelock/commit/5e3f2ec0c5fb17cb2635b60b2b68bc63ab81ca2d Added Reference https://github.com/tox-dev/filelock/pull/834 Added Reference https://github.com/tox-dev/filelock/releases/tag/4.2.1 Added Reference https://github.com/tox-dev/filelock/security/advisories/GHSA-v4x8-3wr5-3wq8