CVE-2026-112940: filelock is a platform-independent file lock for Python

Q: How do I fix CVE-2026-112940?

filelock: upgrade to 4.2.1. Exact commands for each OS are on this page.

Q: Is CVE-2026-112940 being exploited?

CVE-2026-112940 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-112940 affect?

CVE-2026-112940 affects filelock. Severity is high (CVSS 7.1). filelock is a platform-independent file lock for Python. From 3.20.4 until 4.2.1, ReadWriteLock let SQLite reopen the database and side files by name; on POSIX systems an attacker with rename access in a non-sticky parent can swap those nam

Q: How urgent is CVE-2026-112940?

Priority 30/100. High severity; Public exploit reference

Routine

HIGH 7.1UPGRADE

CVE-2026-112940 is a high-severity flaw (CVSS 7.1) affecting filelock. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

filelock is a platform-independent file lock for Python. From 3.20.4 until 4.2.1, ReadWriteLock let SQLite reopen the database and side files by name; on POSIX systems an attacker with rename access in a non-sticky parent can swap those names to cause overwrite or unlink operations, while a writable adjacent hot journal is additionally required for attacker-chosen content overwrites. This issue is fixed in version 4.2.1.

Why this priority

High severity
Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	7.1 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.1% (top 98%)
CISA exploited list	No
Weakness	CWE-363, CWE-59
Published	2026-10-20
Last modified	2026-10-22

Publisher (CNA): GitHub, Inc. · Vendor: tox-dev

Last updated 2026-10-22 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-10-20Published CVE record published
2026-10-22 22:18 UTCUpdated Record last modified

tox-dev filelock UPGRADE

Affected: >= 3.20.4 and < 4.2.1

Fixed in: 4.2.1

Safe to downgrade to: a release before 3.20.4

1. Check installed version

pip show filelock

2. UPGRADE to 4.2.1

pip install --upgrade "filelock>=4.2.1"

3. If no update is available yet, DOWNGRADE to a release before 3.20.4

pip index versions filelock pip install "filelock<3.20.4"

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Exact fixes by distribution

Fedora 46 · diffoscope · FIXED · 335-1.fc46 · FEDORA-2026-e4c4cc0856 · source

sudo dnf upgrade --advisory=FEDORA-2026-e4c4cc0856

Debian 12 · python-filelock · NO FIX YET

Debian 13 · python-filelock · NO FIX YET

RHEL AI (RHEL AI) 3 · rhelai3/bootc-aws-cuda-rhel9 · NO FIX YET

RHEL AI (RHEL AI) 3 · rhelai3/bootc-azure-cuda-rhel9 · NO FIX YET

RHEL AI (RHEL AI) 3 · rhelai3/bootc-azure-rocm-rhel9 · NO FIX YET

RHEL AI (RHEL AI) 3 · rhelai3/bootc-cuda-rhel9 · NO FIX YET

RHEL AI (RHEL AI) 3 · rhelai3/bootc-gaudi-rhel9 · NO FIX YET

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-112940?

filelock: upgrade to 4.2.1. Exact commands for each OS are on this page.

Is CVE-2026-112940 being exploited?

CVE-2026-112940 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-112940 affect?

CVE-2026-112940 affects filelock. Severity is high (CVSS 7.1). filelock is a platform-independent file lock for Python. From 3.20.4 until 4.2.1, ReadWriteLock let SQLite reopen the database and side files by name; on POSIX systems an attacker with rename access in a non-sticky parent can swap those nam

How urgent is CVE-2026-112940?

Priority 30/100. High severity; Public exploit reference

Software pages

Python vulnerabilities · SQLite vulnerabilities

Related CVEs

CVE-2026-112934 MEDIUM 6.1 UPGRADE filelock is a platform-independent file lock for Python

References

← Back to latest CVEs