virtualenv · filelock ReadWriteLock: SQLite reopens the lock database by name, so a planted symlink or journal file makes the lock
Affects virtualenvSource GCVE Database
Not known to be exploited · CVSS 7.1 High : upgrade to 21.14.10 soon.
Data as of 30 Oct 2026, 07:29 UTC
Thin evidence
One scorer or none| CNA (GitHub_M) | CVSS 3.1 | 7.1 |
|---|
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 8% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 21.14.10
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 20 Oct 2026
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 29 Oct 2026.
What to do
Upgrade virtualenv to 21.14.10.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Homebrewvirtualenvpkg:brew/virtualenvOther 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 21.14.10 and later; upgrading to this version or newer remediates the vulnerability. Additionally, ensure that directories containing lock databases are not world-writable or group-writable without the sticky bit set to prevent unauthorized file creation or renaming by other users. Kernel settings fs.protected_regular and fs.protected_hardlinks can also mitigate some attack vectors by restricting file access in sticky world-writable directories.
Description
The filelock ReadWriteLock and AsyncReadWriteLock components use SQLite to manage locks by reopening lock database files by name, which allows a local attacker with write access to the lock directory to plant symlinks or journal files. This can cause the lock user’s process to write attacker-controlled data into the lock user's files, create or unlink files, or cause lock acquisition failures. The vulnerability affects filelock versions 3.20.4 through 4.2.0, with fixed versions starting at 21.14.10. The issue requires a writable directory without the sticky bit and a local attacker with an account on the same host. The CVSS score is 7.1 (High).
References
- github.com/tox-dev/filelock/security/advisories/GHSA-v4x8-3wr5-3wq8 (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-112940 (opens in a new tab)
- github.com/tox-dev/filelock/pull/834 (opens in a new tab)
- github.com/tox-dev/filelock/commit/5e3f2ec0c5fb17cb2635b60b2b68bc63ab81ca2d (opens in a new tab)
- github.com/tox-dev/filelock (opens in a new tab)
- github.com/tox-dev/filelock/releases/tag/4.2.1 (opens in a new tab)