lexicon · filelock: StrictSoftFileLock follows a symbolic link swapped in at <path>.filelock and creates claim files in a
Affects lexiconSource GCVE Database
Not known to be exploited · CVSS 5.8 Medium : upgrade to 3.25.2_5 when convenient.
Data as of 30 Oct 2026, 07:32 UTC
- Patch
- Available – fixed in 3.25.2_5
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:HExploitation evidence
Disclosed: evidence found.
CVE published 29 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 patch is available in filelock version 3.25.2_5 that fixes this issue. Users should upgrade to this fixed version or later. The vulnerability is conditional on the attacker being able to rename the <path>.filelock directory, which is prevented in directories with the sticky bit set and proper ownership. Therefore, ensuring that shared directories where filelock is used have the sticky bit set and proper permissions can mitigate the risk. No additional action is required if the patch is applied or the directory permissions prevent renaming by unauthorized users.
Description
A vulnerability in filelock versions >=3.30.0 and <=4.2.0 allows a local user with write access to a shared directory to exploit a race condition involving symbolic links in the lock coordination directory (<path>.filelock). By swapping this directory with a symbolic link between a check and subsequent operations, the attacker can cause the lock user's process to create claim files in an attacker-chosen directory. This can lead to denial of service by causing stranded claims that block other processes from acquiring the lock until manually force-broken.
References
- github.com/tox-dev/filelock/security/advisories/GHSA-m462-7rxw-wvpg (opens in a new tab)
- github.com/tox-dev/filelock/pull/839 (opens in a new tab)
- github.com/tox-dev/filelock/commit/bfa066d65a1ba9106f86ee9d027f7588b9c77e03 (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)