Auth bypass in Nixos Nix

CVE-2026-110453

Nix before 2.35.3, when unsandboxed on macOS or FreeBSD, incorrectly allows connections made by build users from daemon clients.

Vulnerability class: Broken Access Control

Published 2026-10-14.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Nixos Nix

Weakness classification (CWE)

CWE-863 — Incorrect Authorization

References

discourse.nixos.org/t/security-advisory-for-nix-and-lix-october-2026/80547

Frequently asked questions

What is CVE-2026-110453?: CVE-2026-110453 is a medium-severity vulnerability in Nixos Nix, classified under Incorrect Authorization. CVSS score: 4.3/10. Published 2026-10-14.
How severe is CVE-2026-110453?: Medium severity. CVSS v3 base score is 4.3 out of 10.