CVE-2026-112914: filelock — Exploit & Fix

Description

filelock is a platform-independent file lock for Python. From 4.1.0 until 4.2.1, SoftFileLock can restore a stale marker by name after moving it aside, allowing another local user with rename access in a non-sticky lock directory to swap in a symbolic link and, on a runtime that follows the link and a same-filesystem target, make the lock user hard-link one of its files into the lock directory. This issue is fixed in version 4.2.1.

Is your site exposed to CVE-2026-112914?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

5.3

MEDIUM

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:N

EPSS — Exploit Prediction

0.0016

Probability of exploitation

0.05%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-363 CWE-363

CWE-59 CWE-59

Affected Products

Vendor	Product	Versions
tox-dev	filelock	4.1.0 — 4.2.1

References

Advisories & Patches

https://github.com/tox-dev/filelock/commit/740ff666b62a88496c8d7394e4e6230605e4d62b https://github.com/tox-dev/filelock/pull/843 https://github.com/tox-dev/filelock/security/advisories/GHSA-crv4-6mhj-j5jh

Exploits

https://github.com/tox-dev/filelock/security/advisories/GHSA-crv4-6mhj-j5jh

Other References

https://github.com/tox-dev/filelock/releases/tag/4.2.1

Frequently Asked Questions

What is CVE-2026-112914? +

filelock is a platform-independent file lock for Python. From 4.1.0 until 4.2.1, SoftFileLock can restore a stale marker by name after moving it aside, allowing another local user with rename access in a non-sticky lock directory to swap in a symbolic link and, on a runtime that follows the link and a same-filesystem target, make the lock user hard-link one of its files into the lock directory. This issue is fixed in version 4.2.1. It has a CVSS v3.1 base score of 5.3 (MEDIUM).

How severe is CVE-2026-112914? +

CVE-2026-112914 has a CVSS v3.1 score of 5.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0016, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-112914? +

CVE-2026-112914 affects products from tox-dev, specifically: filelock. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-112914? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2025-62161 10.0

Youki is a container runtime written in Rust. In versions 0.5.6 and below, the initial validation of the source /dev/null …

CVE-2025-62596 10.0

Youki is a container runtime written in Rust. In versions 0.5.6 and below, youki’s apparmor handling performs insufficiently strict write-target …

CVE-2024-27102 9.9

Wings is the server control plane for Pterodactyl Panel. This vulnerability impacts anyone running the affected versions of Wings. The …

CVE-2025-31133 7.8

runc is a CLI tool for spawning and running containers according to the OCI specification. In versions 1.2.7 and below, …

CVE-2025-52881 7.5

runc is a CLI tool for spawning and running containers according to the OCI specification. In versions 1.2.7, 1.3.2 and …

CVE-2025-52565 7.5

runc is a CLI tool for spawning and running containers according to the OCI specification. Versions 1.0.0-rc3 through 1.2.7, 1.3.0-rc.1 …

CVE-2026-112914