lexicon · filelock ReadWriteLock: SQLite reopens the lock database by name, so a planted symlink or journal file makes the lock
Affects lexiconSource GCVE Database
Not known to be exploited · CVSS 7.1 High : upgrade to 3.25.2_5 soon.
Data as of 30 Oct 2026, 07:31 UTC
Thin evidence
One scorer or none| CNA (GitHub_M) | CVSS 3.1 | 7.1 |
|---|
- Patch
- Available – fixed in 3.25.2_5
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 lexicon to 3.25.2_5.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Homebrewlexiconpkg:brew/lexiconOther 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 3.25.2_5. Users should upgrade to this version or later to remediate the vulnerability. Additionally, ensure that directories containing the lock database are not world-writable or group-writable without the sticky bit set. Using sticky bit directories (e.g., /tmp) and enabling kernel protections such as fs.protected_regular=1 or 2 and fs.protected_hardlinks=1 reduces exploitability. No other specific mitigations are required once patched.
Description
The filelock ReadWriteLock and AsyncReadWriteLock components use SQLite databases for locking, but on Linux and other POSIX systems, SQLite reopens the lock database by name, following symlinks and acting on side files like -journal, -wal, and -shm. This behavior allows a local attacker with write permissions in the directory containing the lock database to manipulate these files, causing the lock user to write arbitrary data into their own files, create or unlink files, or cause lock acquisition failures. The vulnerability affects filelock versions from 3.20.4 through 4.2.0, with the fixed version being 3.25.2_5. The CVSS 3.1 score is 7.1 (High), reflecting local attack complexity but high integrity and availability impact. The issue requires a writable directory without the sticky bit and is mitigated by kernel protections and directory permissions.
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)