CVE-2026-64846 (GCVE-0-2026-64846)

Vulnerability from cvelistv5 – Published: 2026-08-20 16:18 – Updated: 2026-08-20 19:32
VLAI
Title
Nix: Arbitrary file truncation outside the sandbox with recursive-nix experimental feature
Summary
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.
Severity
2.8 (Low)
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:N
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-20 19:32 UTC
CWE
  • CWE-61 - UNIX Symbolic Link (Symlink) Following
  • CWE-367 - Time-of-check Time-of-use (TOCTOU) Race Condition
Assigner
GitHub_M CNA under the mitre root
CNA scorecard C 72/100 over 7675 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
NixOS nix Affected: < 2.35.0
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

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