CVE-2026-64846Nix: Arbitrary file truncation outside the sandbox with recursive-nix experimental feature
Updated under an hour ago ()
Does this affect you?
It affects NixOS nix. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
Do this next
Free account, 1 product
Nix is a package manager for Linux and other Unix systems. Prior to 2.35.0, a malicious derivation executed with the recursive-nix experimental feature can exploit a time-of-check/time-of-use race involving final symlink handling in the LocalStore restore path. The race can cause writeFile to follow a substituted final symlink when opening a path with O_TRUNC instead of enforcing FinalSymlink::DontFollow, allowing the Nix process or nix-daemon to create or truncate an empty file outside the build sandbox with the daemon user's permissions. The primitive does not provide arbitrary-content writes and requires winning the race. This issue is fixed in version 2.35.0.
- CVSS
- 2.8 LOW (v3.1, CNA)CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:N
- Weakness (CWE)
- CWE-61, CWE-367
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- GitHub_M
- NVD analysis
- Awaiting Analysis
- Record last updated
- Aug 20, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
NixOS nix nixos:nix (from the name) | before 2.35.0 | CNA record |
References
- https://github.com/NixOS/nix/security/advisories/GHSA-6h4g-g5j9-fm5fx-refsource-confirm
- https://github.com/NixOS/nix/pull/15401x-refsource-misc
- https://github.com/NixOS/nix/commit/26679828f74ee6e82a4100904e6361f993ff5390x-refsource-misc
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.