CVE-2026-64846

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 v3 2.8 LOW

2.8^/10

CVSS v3 : LOW

Vector :

Exploitability : 1.1 / Impact : 1.4

Attack Vector LOCAL

Attack Complexity HIGH

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact LOW

Availability Impact NONE

Scope CHANGED

References

Link	Resource
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

Configurations

No configuration.

History

No history.

Information

Published : 2026-08-20 17:19

Updated : 2026-08-20 20:17

NVD link : CVE-2026-64846

Mitre link : CVE-2026-64846

CVE.ORG link : CVE-2026-64846

JSON object : View

Products Affected

No product.

CWE

CWE-61

UNIX Symbolic Link (Symlink) Following

CWE-367

Time-of-check Time-of-use (TOCTOU) Race Condition

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