CVE-2026-64846
2.8
Vector
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:N
Exploitability: 1.1 / Impact: 1.4
Source: security-advisories@github.com (Secondary)
Description
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.
Related CWEs
CWE-367
Time-of-check Time-of-use (TOCTOU) Race Condition
The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check. This can cause the product to perform invalid actions when the resource is in an unexpected state.
CWE-61
UNIX Symbolic Link (Symlink) Following
The product, when opening a file or directory, does not sufficiently account for when the file is a symbolic link that resolves to a target outside of the intended control sphere. This could allow an attacker to cause the product to operate on unauthorized files.
References (3)
Source: security-advisories@github.com
Source: security-advisories@github.com
Source: security-advisories@github.com
Timeline
No history available yet.