CVE-2026-64846

low

EUVD alias: EUVD-2026-63424

Assigned by CNA: github_m

Published 2026-08-20 · Modified 2026-08-20

Discuss on Community Propose mitigation

CVSS v3

2.8

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:N

CVSS v4 NEW

—

not yet in upstream

VIR risk

2.8

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.

Predictions

Exploit likelihood

29%

Patch ETA

—

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.

Propose a mitigation on Community Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

References

CWEs

CWE-61 CWE-367

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.