CVE-2026-112906
filelock: SoftFileLock evicts a fresh lock file whose watched age another local user's pre-dated file passed on through inode reuse
Description
filelock is a platform-independent file lock for Python. From 4.1.0 until 4.2.1, SoftFileLock versions from 4.1.0 can reuse a stale observation when an attacker pre-dates and removes its own marker, at least two lock-user processes are waiting, coarse or matching modification times preserve the observation, and an honest contender creates a fresh marker on the reused inode, causing that live marker to be removed as stale. This issue is fixed in version 4.2.1.
INFO
Published Date :
Oct. 20, 2026, 3:17 p.m.
Last Modified :
Oct. 27, 2026, 9:06 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 | MEDIUM | MITRE-CVE | ||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update filelock to version 4.2.1 or later.
- Ensure filelock is updated across all affected systems.
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-2026-112906.
| URL | Resource |
|---|---|
| https://github.com/tox-dev/filelock/commit/740ff666b62a88496c8d7394e4e6230605e4d62b | Patch |
| https://github.com/tox-dev/filelock/releases/tag/4.2.1 | Release Notes |
| https://github.com/tox-dev/filelock/security/advisories/GHSA-2g95-wg33-c5x2 | Exploit Mitigation Patch Vendor Advisory |
| https://github.com/tox-dev/filelock/security/advisories/GHSA-2g95-wg33-c5x2 | 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-2026-112906 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-2026-112906
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-2026-112906 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-112906 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. 27, 2026
Action Type Old Value New Value Added CWE CWE-362 Added CPE Configuration OR *cpe:2.3:a:tox-dev:filelock:*:*:*:*:*:python:*:* versions from (including) 4.1.0 up to (excluding) 4.2.1 Added Reference Type GitHub, Inc.: https://github.com/tox-dev/filelock/commit/740ff666b62a88496c8d7394e4e6230605e4d62b Types: Patch Added Reference Type GitHub, Inc.: https://github.com/tox-dev/filelock/releases/tag/4.2.1 Types: Release Notes Added Reference Type CISA-ADP: https://github.com/tox-dev/filelock/security/advisories/GHSA-2g95-wg33-c5x2 Types: Exploit, Mitigation, Patch, Vendor Advisory Added Reference Type GitHub, Inc.: https://github.com/tox-dev/filelock/security/advisories/GHSA-2g95-wg33-c5x2 Types: Exploit, Mitigation, Patch, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Oct. 20, 2026
Action Type Old Value New Value Added Reference https://github.com/tox-dev/filelock/security/advisories/GHSA-2g95-wg33-c5x2 Added SSVC {'id': 'CVE-2026-112906', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-10-20T15:27:04.618631Z'} -
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 4.1.0 until 4.2.1, SoftFileLock versions from 4.1.0 can reuse a stale observation when an attacker pre-dates and removes its own marker, at least two lock-user processes are waiting, coarse or matching modification times preserve the observation, and an honest contender creates a fresh marker on the reused inode, causing that live marker to be removed as stale. 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:N Added CWE CWE-694 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/112xxx/CVE-2026-112906.json">CVE-2026-112906</a> Added Reference https://github.com/tox-dev/filelock/commit/740ff666b62a88496c8d7394e4e6230605e4d62b Added Reference https://github.com/tox-dev/filelock/releases/tag/4.2.1 Added Reference https://github.com/tox-dev/filelock/security/advisories/GHSA-2g95-wg33-c5x2