CVE-2026-112914

filelock: SoftFileLock stale-break restore follows a swapped-in symbolic link and hard-links a file of the user running the lock into the lock directory

MEDIUM
5.3
CVSS Score
Published: October 20, 2026 at 02:26 PM UTC
Updated: October 21, 2026 at 09:17 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
MEDIUM5.3
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

filelock is a platform-independent file lock for Python. From 4.1.0 until 4.2.1, SoftFileLock can restore a stale marker by name after moving it aside, allowing another local user with rename access in a non-sticky lock directory to swap in a symbolic link and, on a runtime that follows the link and a same-filesystem target, make the lock user hard-link one of its files into the lock directory. 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.

4.1.0 ≤ 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-crv4-6mhj-j5jh
x_refsource_MISCPatch
Source: cverecord
https://github.com/tox-dev/filelock/pull/843
x_refsource_MISCRelease Notes
Source: cverecord
https://github.com/tox-dev/filelock/releases/tag/4.2.1

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

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

CVSS

5.3MEDIUMGitHub_M
Attack Vector
LOCAL
Complexity
HIGH
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
HIGH
Availability
NONE
Vector?

Quick Info

StatusANALYZED
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