CVE-2026-64846
LOW
2,8
Source: [email protected]
Attack Vector: local
Attack Complexity: high
Privileges Required: low
User Interaction: none
Scope: changed
Confidentiality: none
Integrity: low
Availability: none
Description
AI Translation Available
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.
61
UNIX Symbolic Link (Symlink) Following
IncompleteCommon Consequences
Security Scopes Affected:
Confidentiality
Integrity
Potential Impacts:
Read Files Or Directories
Modify Files Or Directories
Applicable Platforms
All platforms may be affected
367
Time-of-check Time-of-use (TOCTOU) Race Condition
IncompleteCommon Consequences
Security Scopes Affected:
Integrity
Other
Non-Repudiation
Potential Impacts:
Alter Execution Logic
Unexpected State
Modify Application Data
Modify Files Or Directories
Modify Memory
Other
Hide Activities
Applicable Platforms
All platforms may be affected
https://github.com/NixOS/nix/commit/26679828f74ee6e82a4100904e6361f993ff5390
https://github.com/NixOS/nix/pull/15401
https://github.com/NixOS/nix/security/advisories/GHSA-6h4g-g5j9-fm5f