TI-2026-76856 Aliases CVE-2026-112915 GHSA-cwqr-hh33-gh44

Crafted lock database makes filelock ReadWriteLock acquisitions hang

MEDIUM 58CWE-400Published 2026-10-20 · Updated 2026-10-20

Key facts

Attack vector: Local
Privileges required: Low
User interaction: None
Attack complexity: Low
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · High
Fix status: Partial Red Hat: 15 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-400.

Summary

filelock, a platform-independent file lock for Python, is affected from 3.20.4 before 4.2.1. ReadWriteLock opens a crafted SQLite lock database without bounding schema and query work (CWE-400). A local user with low privileges who can replace that database can make lock acquisition stall or hang, and versions from 3.30.0 repeat this on every acquisition. A public exploit is linked in the references.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

Description from the CNA

filelock is a platform-independent file lock for Python. From 3.20.4 until 4.2.1, ReadWriteLock can open a crafted SQLite lock database without bounding schema and query work, allowing another local user who can replace the database to make acquisition stall or hang; versions from 3.20.4 expose this on initial per-instance opening, and versions from 3.30.0 repeat the exposure on every acquisition. This issue is fixed in version 4.2.1.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV

EPSS 0.00218 12th percentileScored 2026-11-07

Public exploit Yes 1 exploit referenceTagged by NVD

Fix Partial filelock (tox-dev): 4.2.1filelock (PyPI): 4.2.1Red Hat: 15 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: Poc
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
tox-dev	filelock	3.20.4 to before 4.2.1	4.2.1	Patch available	CNA
—	filelock (PyPI)	3.20.4 to before 4.2.1	4.2.1	Patch available	GHSA-cwqr-hh33-gh44

filelock Vendortox-dev Affected 3.20.4 to before 4.2.1 Fixed in 4.2.1 Patch available CNA
filelock (PyPI) Vendor— Affected 3.20.4 to before 4.2.1 Fixed in 4.2.1 Patch available GHSA-cwqr-hh33-gh44

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:tox-dev:filelock::::::python::*	3.20.4 to before 4.2.1	Vulnerable	tox-dev

cpe:2.3:a:tox-dev:filelock:*:*:*:*:*:python:*:* Versions 3.20.4 to before 4.2.1 Vulnerable ·tox-dev

Remediation

Upgrade the PyPI package filelock to version 4.2.1, which fixes the issue. Red Hat's plan is none available for Ansible Automation Platform 2, Red Hat OpenShift AI (RHOAI), Red Hat OpenShift Container Platform 4, Red Hat Satellite 6, Red Hat Enterprise Linux AI (RHEL AI) 3 and other products, and no fix planned for Exploit Intelligence.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

Fix · CNA filelock (tox-dev) Fixed in 4.2.1
Fix · GHSA-cwqr-hh33-gh44 filelock (PyPI) Fixed in 4.2.1 Advisory →

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

Product	Status	Plan or fix
Ansible Automation Orchestrator 2026	Affected	No fix yet: Fix deferred
Exploit Intelligence	Affected	No fix planned: Out of support scope
Lightspeed Core	Affected	No fix yet: Fix deferred
Lightspeed Services for Advanced Cluster Management	Affected	No fix yet: Fix deferred
OpenShift Lightspeed	Affected	No fix yet: Fix deferred
Pen Drive Powered by Red Hat Lightspeed	Affected	No fix yet: Fix deferred
Red Hat AI Inference Server	Affected	No fix yet: Fix deferred
Red Hat Ansible Automation Platform 2	Affected	No fix yet: Fix deferred
Red Hat Ansible Automation Platform Ansible Core 2	Affected	No fix yet: Fix deferred
Red Hat Enterprise Linux AI (RHEL AI) 3	Affected	No fix yet: Fix deferred
Red Hat Lightspeed Services for OCP	Affected	No fix yet: Fix deferred
Red Hat OpenShift AI (RHOAI)	Affected	No fix yet: Fix deferred
Red Hat OpenShift Container Platform 4	Affected	No fix yet: Fix deferred
Red Hat OpenShift Dev Spaces	Affected	No fix yet: Fix deferred
Red Hat Satellite 6	Affected	No fix yet: Fix deferred

Timeline

2026-10-20 Threatist record created from CVE-2026-112915
2026-10-21 Affected versions changed · Red Hat
2026-10-21 CVSS score added · Red Hat
2026-10-28 Alias added: GHSA-cwqr-hh33-gh44
2026-10-28 Fix available: PyPI/[email protected] · GHSA-cwqr-hh33-gh44
2026-10-28 CVSS score added · GHSA-cwqr-hh33-gh44
2026-10-28 Weakness changed · GHSA-cwqr-hh33-gh44
2026-10-28 6 new references · GHSA-cwqr-hh33-gh44

References

Exploit 1

https://github.com/tox-dev/filelock/security/advisories/GHSA-cwqr-hh33-gh44

Patch 2

Advisory 1

https://nvd.nist.gov/vuln/detail/CVE-2026-112915

Other 2

TI-2026-76862 Symlink race in filelock ReadWriteLock lets attackers overwrite files CVSS 3.1HIGH 7.1
TI-2026-76853 filelock soft locks adopt directories created by other local users CVSS 3.1MEDIUM 6.3
TI-2026-76859 Symlink following in filelock ReadWriteLock redirects SQLite database CVSS 3.1MEDIUM 6.1
TI-2026-76857 Unsafe holder record refresh in filelock SoftReadWriteLock CVSS 3.1MEDIUM 6.1
TI-2026-76852 filelock UnixFileLock truncates files placed on the lock path CVSS 3.1MEDIUM 6.1
TI-2026-76861 SoftFileLock in filelock trusts forged PIDs and removes live markers CVSS 3.1MEDIUM 4.7

See all 14 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences