CVE-2026-112911
filelock: StrictSoftFileLock and SoftReadWriteLock adopt a protocol directory another user created first, losing mutual exclusion
Description
filelock is a platform-independent file lock for Python. From 3.30.0 until 4.2.1, StrictSoftFileLock versions from 3.30.0 and SoftReadWriteLock versions from 4.0.0 can adopt a protocol directory created first by another local user in a shared parent directory, allowing that user to alter protocol state and admit concurrent holders. This issue is fixed in version 4.2.1.
INFO
Published Date :
Oct. 20, 2026, 3:17 p.m.
Last Modified :
Oct. 21, 2026, 9:21 p.m.
Remotely Exploit :
No
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | MITRE-CVE | ||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update filelock to version 4.2.1 or later.
- Ensure proper file permission 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-2026-112911.
| URL | Resource |
|---|---|
| https://github.com/tox-dev/filelock/commit/bfa066d65a1ba9106f86ee9d027f7588b9c77e03 | Patch |
| https://github.com/tox-dev/filelock/pull/839 | Patch |
| https://github.com/tox-dev/filelock/releases/tag/4.2.1 | Release Notes |
| https://github.com/tox-dev/filelock/security/advisories/GHSA-9c4x-gm8v-wgc4 | 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-2026-112911 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-2026-112911
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-2026-112911 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-112911 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.
-
Initial Analysis by [email protected]
Oct. 21, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:tox-dev:filelock:*:*:*:*:*:python:*:* versions from (including) 3.30.0 up to (excluding) 4.2.1 Added Reference Type GitHub, Inc.: https://github.com/tox-dev/filelock/commit/bfa066d65a1ba9106f86ee9d027f7588b9c77e03 Types: Patch Added Reference Type GitHub, Inc.: https://github.com/tox-dev/filelock/pull/839 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-9c4x-gm8v-wgc4 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 3.30.0 until 4.2.1, StrictSoftFileLock versions from 3.30.0 and SoftReadWriteLock versions from 4.0.0 can adopt a protocol directory created first by another local user in a shared parent directory, allowing that user to alter protocol state and admit concurrent holders. This issue is fixed in version 4.2.1. Added CVSS V3.1 AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H Added CWE CWE-283 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/112xxx/CVE-2026-112911.json">CVE-2026-112911</a> Added Reference https://github.com/tox-dev/filelock/commit/bfa066d65a1ba9106f86ee9d027f7588b9c77e03 Added Reference https://github.com/tox-dev/filelock/pull/839 Added Reference https://github.com/tox-dev/filelock/releases/tag/4.2.1 Added Reference https://github.com/tox-dev/filelock/security/advisories/GHSA-9c4x-gm8v-wgc4