The Nix, Lix, and Guix package managers default to using temporary build directories in a world-readable and world-writable location. This allows standard users to deceive the package manager into using directories with pre-existing content, potentially leading to unauthorized actions or data manipulation. This affects Nix before 2.24.15, 2.26.4, 2.28.4, and 2.29.1; Lix before 2.91.2, 2.92.2, and 2.93.1; and Guix before 1.4.0-38.0e79d5b.
https://security.snyk.io/vuln/?search=CVE-2025-52991
https://security-tracker.debian.org/tracker/CVE-2025-52991
https://lix.systems/blog/2025-06-24-lix-cves/
https://guix.gnu.org/en/blog/2025/privilege-escalation-vulnerabilities-2025/
https://discourse.nixos.org/t/security-advisory-privilege-escalations-in-nix-lix-and-guix/66017