CVE-2025-68146: Pytorch · filelock has a TOCTOU race condition which allows symlink attacks during lock file creation
Affects pytorchSource GCVE Database
Not known to be exploited · CVSS 6.3 Medium : upgrade to 2.10.0 or 2.1.2 when convenient.
Data as of 31 Oct 2026, 16:06 UTC
- Patch
- Available – fixed in 2.10.0, 2.1.2
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 16 Dec 2025
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 30 Oct 2026.
What to do
Upgrade pytorch to 2.10.0 or 2.1.2.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Homebrewpytorchpkg:brew/pytorchOther 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 3.20.1 and later, which should be applied immediately. The patch prevents symlink following during lock file creation by adding O_NOFOLLOW on Unix and reparse point checks on Windows. If upgrading immediately is not possible, partial mitigations include using SoftFileLock instead of UnixFileLock/WindowsFileLock, restricting lock file directory permissions to prevent untrusted symlink creation, and monitoring lock directories for suspicious symlinks. However, these workarounds do not fully eliminate the race condition, so upgrading is strongly recommended.
Description
A TOCTOU race condition in the filelock library used by PyTorch and other tools allows local attackers to exploit a time gap during lock file creation to create symlinks that cause arbitrary user files to be truncated. This affects Unix, Linux, macOS, and Windows systems. The vulnerability can corrupt critical files such as configuration files, CPU ISA caches, or model checkpoints, potentially causing application crashes or data loss. The issue is fixed in filelock version 3.20.1 by preventing symlink following during file open operations.
References
- github.com/tox-dev/filelock/security/advisories/GHSA-w853-jp5j-5j7f (opens in a new tab)
- github.com/tox-dev/filelock/commit/4724d7f8c3393ec1f048c93933e6e3e6ec321f0e (opens in a new tab)
- github.com/tox-dev/filelock (opens in a new tab)
- github.com/tox-dev/filelock/releases/tag/3.20.1 (opens in a new tab)
- learn.microsoft.com/en-us/windows/win32/fileio/file-attribute-constants (opens in a new tab)
- pubs.opengroup.org/onlinepubs/9699919799/functions/open.html (opens in a new tab)