Quick answers
- Is CVE-2026-112935 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-112935 being exploited in the wild.
- How severe is CVE-2026-112935?
- Medium severity, with a CVSS score of 4.7, published 20 October 2026.
- Which products and versions are affected?
- filelock (PyPI) >= 3.22.0, <= 4.2.0, ECOSYSTEM:introduced=3.22.0,fixed=4.2.1; Tox-Dev Filelock 3.22.0 to 4.2.0.
- Is there a fix for CVE-2026-112935?
- 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-2026-112935 attacked?
- It is attacked with local access, in a software library.
- Am I affected by CVE-2026-112935?
- 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 3.22.0 through 4.2.1 in the SoftFileLock class. An attacker can break a stale marker after freeing their own marker, causing a live successor created on a reused inode to be incorrectly removed if its modification time is not newer than a saved observation, allowing two lock holders to be admitted simultaneously. The attack requires local access to manipulate file system markers and timing conditions.
Affected products
- tox-dev filelock 3.22.0 to 4.2.0
Identifiers
- CVE-2026-112935
- GHSA-fq56-3cx3-fjxp
Timeline
- 2026-10-20: disclosed
- 2026-10-17: patched: Fix committed and merged