Is CVE-2026-112937 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-112937 being exploited in the wild.

How severe is CVE-2026-112937?

Medium severity, with a CVSS score of 6.1, 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-2026-112937?

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-2026-112937 attacked?

It is attacked with local access.

Am I affected by CVE-2026-112937?

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-2026-112937: filelock ReadWriteLock insecure temporary directory cleanup

Q: Is there a fix for CVE-2026-112937?

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-2026-112937 attacked?

It is attacked with local access.

Q: Am I affected by CVE-2026-112937?

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-2026-112937 · Severity: medium · CVSS 6.1 · Published 2026-10-20

filelock is a Python library providing cross-platform file locking for applications. A flaw in the ReadWriteLock component allows local attackers to exploit insecure cleanup of temporary directories, potentially leading to unauthorized file operations or data tampering by other users on the same system.

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

Quick answers

Is CVE-2026-112937 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-112937 being exploited in the wild.
How severe is CVE-2026-112937?: Medium severity, with a CVSS score of 6.1, 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-2026-112937?: 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-2026-112937 attacked?: It is attacked with local access.
Am I affected by CVE-2026-112937?: 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

The vulnerability exists in filelock versions 4.1.0 through 4.2.1 where ReadWriteLock can remove randomized .filelock-* private hard-link directories during cleanup. An attacker with local access and rename permissions in a non-sticky parent directory can observe live names or craft a dead-owner sweep name, then rename a sibling directory onto it for deletion. The attack requires local access and write permissions in the parent directory containing the lock files.

Affected products

tox-dev filelock 4.1.0 to 4.2.1

Identifiers

CVE-2026-112937
GHSA-jqc4-5cvw-7w85

Timeline

2026-10-20: disclosed

References

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