CVE-2026-112938: tox-dev filelock · Race Condition Enabling Link Following
Affects tox-dev filelockSource CVE Database V5
Not known to be exploited · CVSS 5.8 Medium : upgrade to 4.2.1 when convenient.
Data as of 5 Nov 2026, 22:33 UTC
Thin evidence
One scorer or none| CNA (GitHub_M) | CVSS 3.1 | 5.8 |
|---|
- Patch
- Available – fixed in 4.2.1
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 5 Nov 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 5 Nov 2026.
What to do
Upgrade tox-dev filelock to 4.2.1.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| tox-devfilelock | Affected
| Fixed in
|
AI-suggested
Upgrade to filelock version 4.2.1 or later, where this race condition vulnerability is fixed. No other mitigations are specified or required.
Description
A race condition vulnerability exists in the tox-dev filelock Python package versions 3.30.0 through 4.2.0 on POSIX platforms. The issue involves StrictSoftFileLock and AsyncStrictSoftFileLock classes where a symbolic link can be swapped in between directory validation and use, allowing local users to manipulate lock claim files. This can lead to claim files being created or stranded in unintended directories, potentially causing lock acquisition timeouts or allowing two processes into a critical section. The vulnerability is fixed in version 4.2.1.
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/aaa18595d29795fab599a69d6b184d9a505dab4b (opens in a new tab)
- github.com/tox-dev/filelock/commit/bfa066d65a1ba9106f86ee9d027f7588b9c77e03 (opens in a new tab)
- github.com/tox-dev/filelock/releases/tag/4.2.1 (opens in a new tab)