Is CVE-2026-112914 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-112914 being exploited in the wild.

How severe is CVE-2026-112914?

Medium severity, with a CVSS score of 5.3, published 20 October 2026.

Which products and versions are affected?

filelock (PyPI) >= 4.1.0, <= 4.2.0, ECOSYSTEM:introduced=4.1.0,fixed=4.2.1; Tox-Dev Filelock 4.1.0 to 4.2.1.

Is there a fix for CVE-2026-112914?

Yes. filelock (PyPI): upgrade to 4.2.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-112914 attacked?

It is attacked with local access, in a software library.

Am I affected by CVE-2026-112914?

Check whether you run filelock (PyPI) or Tox-Dev Filelock at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-112914: filelock SoftFileLock symlink attack via stale marker

Q: Is there a fix for CVE-2026-112914?

Yes. filelock (PyPI): upgrade to 4.2.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-112914 attacked?

It is attacked with local access, in a software library.

Q: Am I affected by CVE-2026-112914?

Check whether you run filelock (PyPI) or Tox-Dev Filelock at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-112914 · Severity: medium · CVSS 5.3 · Published 2026-10-20

filelock is a Python library that implements cross-platform file locking for coordinating access to shared resources. A vulnerability in versions 4.1.0 through 4.2.1 allows a local attacker with rename permissions to exploit a race condition by swapping a moved lock marker with a symbolic link, potentially forcing the lock holder to create hard links into the lock directory. This could lead to privilege escalation or file corruption on systems where the attacker and lock holder are distinct users.

Technologies: filelock (PyPI), Tox-Dev Filelock. Vendors: PyPI, Tox-Dev.

Quick answers

Is CVE-2026-112914 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-112914 being exploited in the wild.
How severe is CVE-2026-112914?: Medium severity, with a CVSS score of 5.3, published 20 October 2026.
Which products and versions are affected?: filelock (PyPI) >= 4.1.0, <= 4.2.0, ECOSYSTEM:introduced=4.1.0,fixed=4.2.1; Tox-Dev Filelock 4.1.0 to 4.2.1.
Is there a fix for CVE-2026-112914?: Yes. filelock (PyPI): upgrade to 4.2.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-112914 attacked?: It is attacked with local access, in a software library.
Am I affected by CVE-2026-112914?: Check whether you run filelock (PyPI) or Tox-Dev Filelock at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

filelock (PyPI): upgrade to 4.2.1 or later
```
pip install "filelock>=4.2.1"
```

Technical details

SoftFileLock implementations fail to prevent symlink attacks when restoring a stale lock marker that was temporarily moved aside. An attacker with local filesystem access and rename permissions in the lock directory can replace the moved marker with a symlink pointing to a same-filesystem target, which the lock user will follow and hard-link. The vulnerability is a time-of-check-time-of-use (TOCTOU) race condition between moving the marker and checking it.

Affected products

tox-dev filelock 4.1.0 to 4.2.1

Identifiers

CVE-2026-112914
GHSA-crv4-6mhj-j5jh

Timeline

2026-10-20: disclosed
2026-10-17: patched

References

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