Absolute Path Traversal in nix - #VU129557
Published: May 4, 2026
Vulnerability identifier: #VU129557
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: N/A
CWE-ID: CWE-36
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: nixos.org
Affected software:
nix
nix
Detailed vulnerability description
The vulnerability allows a remote attacker to modify files outside the intended extraction directory.
The vulnerability exists due to absolute path traversal in the archive unpacking functionality of nix-prefetch-url --unpack, nix store prefetch-file --unpack, and builtin:unpack-channel when processing archives containing entries with absolute paths. A remote attacker can supply a specially crafted archive to modify files outside the intended extraction directory.
User interaction is required to unpack an untrusted archive. The builtin:unpack-channel builder is sandboxed in sandboxed builds.
Remediation
Install security update from vendor's website.