Python filelock:
Affects python-filelockSource GCVE Database
Not known to be exploited · CVSS 6.3 Medium · fixed in 3.0.4-1ubuntu0.1~esm1 : update python-filelock when convenient.
Data as of 9 Nov 2026, 14:32 UTC
- Patch
- Available – fixed in 3.0.4-1ubuntu0.1~esm1, 3.6.0-1ubuntu0.1~esm1, 3.13.1-1ubuntu0.1~esm1
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 16 Dec 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 9 Nov 2026.
What to do
Upgrade the Ubuntu python-filelock to 3.0.4-1ubuntu0.1~esm1 (package) or 3.6.0-1ubuntu0.1~esm1 (package) or 3.13.1-1ubuntu0.1~esm1 (package).
Patches and advisories
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.10python-filelockpkg:deb/ubuntu/python-filelock?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 25.10python-filelockpkg:deb/ubuntu/python-filelock?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu Pro 24.04 LTSpython-filelockpkg:deb/ubuntu/python-filelock?arch=source&distro=esm-apps/nobleOther threats | Affected
| Fixed in
|
Ubuntu Pro 22.04 LTSpython-filelockpkg:deb/ubuntu/python-filelock?arch=source&distro=esm-apps/jammyOther threats | Affected
| Fixed in
|
Ubuntu Pro 18.04 LTSpython-filelockpkg:deb/ubuntu/python-filelock?arch=source&distro=esm-apps/bionicOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix is available in filelock version 3.20.1 and in Ubuntu package versions 3.0.4-1ubuntu0.1~esm1, 3.6.0-1ubuntu0.1~esm1, and 3.13.1-1ubuntu0.1~esm1. Upgrading to these versions is strongly recommended. If immediate upgrade is not possible, use SoftFileLock instead of UnixFileLock/WindowsFileLock, restrict lock file directory permissions to 0700 to prevent untrusted symlink creation, and monitor lock file directories for suspicious symlinks. These mitigations provide only partial protection and do not fully prevent exploitation.
Description
Python filelock versions prior to 3.20.1 contain a Time-of-Check-Time-of-Use (TOCTOU) race condition vulnerability that allows local attackers to corrupt or truncate arbitrary user files via symlink attacks. This affects Unix, Linux, macOS, and Windows systems where filelock checks for a file's existence before opening it with truncation, enabling attackers to exploit the time gap by creating symlinks to victim files. The vulnerability requires local filesystem access and symlink creation capability. The issue is fixed in version 3.20.1. Partial mitigations include using SoftFileLock, restricting lock file directory permissions, and monitoring for suspicious symlinks, but upgrading is strongly recommended.
References
- ubuntu.com/security/CVE-2025-68146 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-68146 (opens in a new tab)
- github.com/tox-dev/filelock/security/advisories/GHSA-w853-jp5j-5j7f (opens in a new tab)
- github.com/tox-dev/filelock/pull/461 (opens in a new tab)
- github.com/tox-dev/filelock/commit/4724d7f8c3393ec1f048c93933e6e3e6ec321f0e (opens in a new tab)
- github.com/tox-dev/filelock/releases/tag/3.20.1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7999-1 (opens in a new tab)