virtualenvwrapper · filelock ReadWriteLock: a crafted lock database makes every acquire stall or hang regardless of timeout
Affects virtualenvwrapperSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium : upgrade to 6.1.1_4 when convenient.
Data as of 30 Oct 2026, 06:59 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 12% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.1.1_4
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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 virtualenvwrapper to 6.1.1_4.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Homebrewvirtualenvwrapperpkg:brew/virtualenvwrapperOther 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 virtualenvwrapper version 6.1.1_4. Users should upgrade to this version or later to resolve the issue. Additionally, restricting write permissions on the lock directory and ensuring it is a sticky directory can prevent untrusted users from replacing or creating the lock database file, mitigating the risk. On Linux, enabling the kernel setting fs.protected_regular=2 can also help protect against unauthorized file replacement in world-writable sticky directories like /tmp. No other action is required once patched or proper directory permissions are enforced.
Description
The filelock library's ReadWriteLock and AsyncReadWriteLock use an SQLite-backed lock database. A crafted lock database file placed by a local user at the lock path can cause every acquire operation to stall or hang indefinitely, ignoring timeout and blocking parameters. This results in a denial of service affecting availability only, without compromising confidentiality or integrity. The issue affects filelock versions 3.20.4 through 4.2.0. A fix is available in version 6.1.1_4 of the related virtualenvwrapper product.
References
- github.com/tox-dev/filelock/security/advisories/GHSA-cwqr-hh33-gh44 (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-112915 (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)