gam · filelock: SoftReadWriteLock holder refresh writes through a hard link and hangs on a named pipe that another local
Affects gamSource GCVE Database
Not known to be exploited · CVSS 6.1 Medium.
Data as of 9 Nov 2026, 20:04 UTC
Thin evidence
One scorer or none| CNA (GitHub_M) | CVSS 3.1 | 6.1 |
|---|
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/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 9 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Homebrewgampkg:brew/gamOther 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
Mitigation involves ensuring that the lock's .rw directory tree is not owned or writable by untrusted local users, especially in sticky world-writable directories like /tmp. Administrators should verify that kernel settings such as fs.protected_hardlinks are enabled (set to 1) on Linux systems to prevent unauthorized hard links. Avoid placing lock directories in locations where other local users can rename or replace files. Monitor vendor advisories for any forthcoming patches or updates.
Description
CVE-2026-112934 describes a vulnerability in the SoftReadWriteLock mechanism used by the filelock library versions 4.0.0 through 4.2.0. The flaw allows a local user who owns the lock's .rw directory tree to interfere with the lock holder's refresh operations by replacing the holder record file with a FIFO (named pipe) or a hard link. This can cause the lock holder's write or read lock operations to hang indefinitely and prevent the heartbeat thread from running, leading to a state where two processes believe they hold the write lock simultaneously. The vulnerability requires local access and specific filesystem conditions, such as permissive hard-link policies on Linux or default macOS/BSD behavior. The impact includes denial of service (availability) and low integrity degradation due to partial overwriting of private files.
References
- github.com/tox-dev/filelock/security/advisories/GHSA-fj95-fr6c-h845 (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-112934 (opens in a new tab)
- github.com/tox-dev/filelock/pull/842 (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)