TI-2026-76859 Aliases CVE-2026-112936 GHSA-j8f7-rjxc-mr56

Symlink following in filelock ReadWriteLock redirects SQLite database

MEDIUM 60CWE-59Published 2026-10-20 · Updated 2026-10-20

Key facts

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

Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat.

Summary

filelock for Python affects versions from 3.20.4 before 4.0.9. ReadWriteLock and AsyncReadWriteLock pass the lock path to SQLite without rejecting a final symbolic link (CWE-59). A local user who can create names in the lock directory can redirect database creation and locking, or split mutual exclusion between targets. 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 4.0.9, ReadWriteLock and AsyncReadWriteLock versions from 3.20.4 resolve the lock path and pass it to SQLite without rejecting a final symbolic link, allowing another local user who can create names in the lock directory to redirect database creation and locking or split mutual exclusion between targets. This issue is fixed in version 4.0.9.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV

EPSS 0.00232 14th percentileScored 2026-11-07

Public exploit Yes 1 exploit referenceTagged by NVD

Fix Partial filelock (tox-dev): 4.0.9filelock (PyPI): 4.0.9Red 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 4.0.9	4.0.9	Patch available	CNA
—	filelock (PyPI)	3.20.4 to before 4.0.9	4.0.9	Patch available	GHSA-j8f7-rjxc-mr56

filelock Vendortox-dev Affected 3.20.4 to before 4.0.9 Fixed in 4.0.9 Patch available CNA
filelock (PyPI) Vendor— Affected 3.20.4 to before 4.0.9 Fixed in 4.0.9 Patch available GHSA-j8f7-rjxc-mr56

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:tox-dev:filelock::::::python::*	3.20.4 to before 4.0.9	Vulnerable	tox-dev

cpe:2.3:a:tox-dev:filelock:*:*:*:*:*:python:*:* Versions 3.20.4 to before 4.0.9 Vulnerable ·tox-dev

Remediation

The PyPI filelock package is fixed in version 4.0.9, so upgrade to that version. Red Hat plans no fix for Exploit Intelligence and has no fix available for Ansible Automation Orchestrator 2026, Lightspeed Core, Lightspeed Services for Advanced Cluster Management, OpenShift Lightspeed, and other products.

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

Fix · CNA filelock (tox-dev) Fixed in 4.0.9
Fix · GHSA-j8f7-rjxc-mr56 filelock (PyPI) Fixed in 4.0.9 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-2026-112936
2026-10-20 CISA SSVC decision points changed
2026-10-21 Affected versions changed · Red Hat
2026-10-21 CVSS score added · Red Hat
2026-10-28 Alias added: GHSA-j8f7-rjxc-mr56
2026-10-28 Fix available: PyPI/[email protected] · GHSA-j8f7-rjxc-mr56
2026-10-28 CVSS score added · GHSA-j8f7-rjxc-mr56
2026-10-28 Weakness changed · GHSA-j8f7-rjxc-mr56
2026-10-28 5 new references · GHSA-j8f7-rjxc-mr56

References

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-2026-76857 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-2026-76856 Crafted lock database makes filelock ReadWriteLock acquisitions hang CVSS 3.1MEDIUM 5.5
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