lexicon · filelock: On Windows an oplock on a soft lock's marker holds SoftFileLock.acquire() past its timeout and blocks the
Affects lexiconSource GCVE Database
Not known to be exploited · CVSS 2.5 Low : upgrade to 3.25.2_5 when convenient.
Data as of 30 Oct 2026, 07:33 UTC
- Patch
- Available – fixed in 3.25.2_5
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:LExploitation 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 fix is available in filelock version 3.25.2_5. Users should upgrade to this version or later to resolve the issue. No other mitigation is required as the vulnerability depends on a stale marker file and local read access. The maintainers have addressed the problem in the specified fixed version.
Description
On Windows, certain soft lock implementations in filelock (versions 3.22.0 through 4.2.0) can be blocked indefinitely due to Windows opportunistic locks (oplocks) on the lock marker file. Another local user with read access can take a Level 1 oplock on a stale marker file and never release it, causing SoftFileLock.acquire() calls to hang past their timeout. This results in partial availability impact without compromising confidentiality or integrity. The issue is fixed in filelock version 3.25.2_5.
References
- github.com/tox-dev/filelock/security/advisories/GHSA-567q-5qvw-pf92 (opens in a new tab)
- github.com/tox-dev/filelock/pull/835 (opens in a new tab)
- github.com/tox-dev/filelock/commit/e1e825b1992f69fb6b346dc395d5ae4893536c0a (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)