poetry · filelock: SoftFileLock stale-lock break removes a live lock file on a reused inode number and admits two holders
Affects poetrySource GCVE Database
Not known to be exploited · CVSS 4.7 Medium : upgrade to 2.5.1_1 when convenient.
Data as of 30 Oct 2026, 08:30 UTC
Thin evidence
One scorer or none| CNA (GitHub_M) | CVSS 3.1 | 4.7 |
|---|
- Patch
- Available – fixed in 2.5.1_1
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:NExploitation 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 poetry to 2.5.1_1.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Homebrewpoetrypkg:brew/poetryOther 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 4.2.1 and later that addresses this issue. Users should upgrade to this fixed version to mitigate the vulnerability. The vulnerability only affects soft file locks on certain filesystems and configurations; using StrictSoftFileLock or avoiding shared sticky directories for locks can reduce risk.
Description
A vulnerability in filelock versions 3.22.0 through 4.2.0 allows a local user with write access to a sticky shared directory (e.g., /tmp) to cause two processes of the lock owner to simultaneously hold the same soft file lock. This occurs due to inode reuse and a race condition in stale-lock breaking logic, which can lead to integrity issues where two holders write protected data without detection.
References
- github.com/tox-dev/filelock/security/advisories/GHSA-fq56-3cx3-fjxp (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-112935 (opens in a new tab)
- github.com/tox-dev/filelock/pull/843 (opens in a new tab)
- github.com/tox-dev/filelock/commit/740ff666b62a88496c8d7394e4e6230605e4d62b (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)