---
id: CVE-2026-112934
title: >-
  filelock: SoftReadWriteLock holder refresh writes through a hard link and
  hangs on a named pipe that another local user renames over its record
summary: >-
  filelock is a platform-independent file lock for Python. From 4.0.0 until
  4.2.1, SoftReadWriteLock refreshes holder records by name, allowing another
  local user with rename access to the lock directory to replace a record with a
  named pi…
severity: medium
cvss: 6.1
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H'
cvssSource: cna
cwe:
  - CWE-62
vendor: tox-dev
product: filelock
affected:
  - 'filelock >= 4.0.0, < 4.2.1'
published: '2026-10-20'
updated: '2026-10-20'
sourceUpdated: '2026-10-20T14:30:43.736Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-112934'
references:
  - url: >-
      https://github.com/tox-dev/filelock/security/advisories/GHSA-fj95-fr6c-h845
    label: >-
      https://github.com/tox-dev/filelock/security/advisories/GHSA-fj95-fr6c-h845
  - url: 'https://github.com/tox-dev/filelock/pull/842'
    label: 'https://github.com/tox-dev/filelock/pull/842'
  - url: >-
      https://github.com/tox-dev/filelock/commit/bfa066d65a1ba9106f86ee9d027f7588b9c77e03
    label: >-
      https://github.com/tox-dev/filelock/commit/bfa066d65a1ba9106f86ee9d027f7588b9c77e03
  - url: 'https://github.com/tox-dev/filelock/releases/tag/4.2.1'
    label: 'https://github.com/tox-dev/filelock/releases/tag/4.2.1'
tags:
  - cve.org
ingestedAt: '2026-10-20T15:09:24.123Z'
---

## Overview

filelock is a platform-independent file lock for Python. From 4.0.0 until 4.2.1, SoftReadWriteLock refreshes holder records by name, allowing another local user with rename access to the lock directory to replace a record with a named pipe and stall the lock, or under a permissive hard-link policy to link a reachable target file and cause the lock user to write through it. This issue is fixed in version 4.2.1.

## Affected

- `filelock >= 4.0.0, < 4.2.1`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.