CVE-2026-112940

filelock ReadWriteLock: SQLite reopens the lock database by name, so a planted symlink or journal file makes the lock user's process overwrite or unlink its own files

HIGH
7.1
CVSS Score
Published: October 20, 2026 at 02:41 PM UTC
Updated: October 22, 2026 at 10:18 PM UTC
1 product affected across 1 vendorFilelock

Using filelock by tox-dev?

Get instant alerts when new vulnerabilities affect filelock - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
HIGH7.1
Exploit prediction
EPSS 0.2%
SSVC
PoC

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

3.20.4 ≤ v < 4.2.1

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (4)

x_refsource_CONFIRMExploitMitigationPatchVendor Advisory
Source: cverecord
https://github.com/tox-dev/filelock/security/advisories/GHSA-v4x8-3wr5-3wq8
x_refsource_MISCPatch
Source: cverecord
https://github.com/tox-dev/filelock/pull/834
x_refsource_MISCRelease Notes
Source: cverecord
https://github.com/tox-dev/filelock/releases/tag/4.2.1

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.1HIGHGitHub_M
Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-363CWE-59

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card