# CVE-2026-110450: Nix privilege escalation via repair operation

Source: https://junglewise.ai/threats/cve-2026-110450-nix-before-2-35-3-and-lix-before-2-95-4-allow-privilege  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-14. Updated: 2026-10-16  
License: CC BY 4.0 with a link back

CVE-2026-110450 · Severity: high · CVSS 8 · Published 2026-10-14

Nix and Lix are package managers that build and manage software dependencies. A flaw in their repair operation allows unprivileged users to destroy and replace legitimate package store files before verification, enabling local privilege escalation to root. This affects systems that run untrusted code or multi-user installations where unprivileged users can access the daemon.

Technologies: [Lix](https://junglewise.ai/threats/technologies/lix-lix), [Nixos Nix](https://junglewise.ai/threats/technologies/nix). Vendors: [Lix](https://junglewise.ai/threats/vendors/lix), [Nixos](https://junglewise.ai/threats/vendors/nixos).

## Quick answers

**Is CVE-2026-110450 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-110450 being exploited in the wild.

**How severe is CVE-2026-110450?** High severity, with a CVSS score of 8, published 14 October 2026.

**Which products and versions are affected?** Lix 2.95.3 and earlier, 2.94.2 and earlier; Nixos Nix 2.35.2 and earlier (2.28.x through 2.35.x).

**Is there a fix for CVE-2026-110450?** Yes: fixed in Nix 2.35.3, 2.34.9, 2.31.6, 2.30.6, 2.28.8; Lix 2.95.4, 2.94.3, 2.96.0. Until then: Restrict access to the Nix daemon on multi-user installations to trusted users only, or disable unprivileged repair operations until upgrading. Users of fresh multi-user installations should verify store directory ownership is root rather than the invoking user. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-110450 attacked?** It is attacked with local access, in a software library.

**Am I affected by CVE-2026-110450?** Check whether you run Lix or Nixos Nix at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in Nix 2.35.3, 2.34.9, 2.31.6, 2.30.6, 2.28.8; Lix 2.95.4, 2.94.3, 2.96.0

Restrict access to the Nix daemon on multi-user installations to trusted users only, or disable unprivileged repair operations until upgrading. Users of fresh multi-user installations should verify store directory ownership is root rather than the invoking user.

## Technical details

CVE-2026-110450 is a time-of-check-time-of-use (TOCTOU) vulnerability in the repair operation where store paths are destroyed and replaced before content verification. This affects multi-user daemon installations on Linux and macOS where unprivileged users can interact with the daemon. An attacker with local access can exploit this to achieve root privilege escalation by manipulating store paths.

## Affected products

- NixOS Nix 2.35.2 and earlier (2.28.x through 2.35.x)
- Lix Lix 2.95.3 and earlier, 2.94.2 and earlier

## Timeline

- 2026-10-13: disclosed: Security advisory published on NixOS Discourse
- 2026-10-14: patched: Fixed versions released: Nix 2.35.3 and Lix 2.95.4

## References

- [https://discourse.nixos.org/t/security-advisory-for-nix-and-lix-october-2026/80547](https://discourse.nixos.org/t/security-advisory-for-nix-and-lix-october-2026/80547)

## Related threats

- [Nix daemon improper authorization of clients on macOS and FreeBSD](https://junglewise.ai/threats/cve-2026-110453-nix-before-2-35-3-when-unsandboxed-on-macos-or-freebsd)
- [Nix multi-user installer improper file ownership](https://junglewise.ai/threats/cve-2026-110452-the-multi-user-installer-in-nix-before-2-35-3-sets-the-ownership)
- [Nix Seatbelt sandbox escape on macOS](https://junglewise.ai/threats/cve-2026-110451-nix-before-2-35-3-and-lix-before-2-95-4-on-macos-allow-a)
- [Nix integer overflow in list allocation](https://junglewise.ai/threats/cve-2026-110449-nix-before-2-35-3-and-lix-before-2-95-4-have-an-integer-overflow)
- [Nix package manager time-of-check/time-of-use in symlink handling](https://junglewise.ai/threats/cve-2026-64846-nix-package-manager-time-of-check-time-of-use-in-symlink-handling)