CVE-2025-54800: Nixos Hydra

Medium severity, CVSS 6.1. EPSS: 0.2% chance of exploitation in the next 30 days.

Hydra is a continuous integration service for Nix based projects. Prior to commit dea1e16, a malicious package can introduce arbitrary JavaScript code into the Hydra database that is automatically evaluated in a client's browser when anyone visits the build page. This could be done by a third-party project as part of its build process. This also happens in other places like with hydra-release-name. This issue has been patched by commit dea1e16. A workaround involves either not building untrusted packages or not visiting the builds page.

Affected products

• Nixos Hydra: before 2025-08-12 (fixed in 2025-08-12)

Published 2025-08-12. Last modified 2026-06-17.