XSS in Nixos Hydra
CVE-2025-54800
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.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.002 (9.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 9th percentile — 9.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000
Affected products
- Nixos Hydra — versions < dea1e168f590efb27db32dbacc82b09e15f8ae4b
Weakness classification (CWE)
Public proof-of-concept exploits
References
- github.com/NixOS/hydra/security/advisories/GHSA-7qwg-q53v-vh99 (Patch, Vendor Advisory)
- github.com/NixOS/hydra/commit/dea1e168f590efb27db32dbacc82b09e15f8ae4b (Patch)
Frequently asked questions
- What is CVE-2025-54800?
- CVE-2025-54800 is a medium-severity vulnerability in Nixos Hydra, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2025-08-12.
- How severe is CVE-2025-54800?
- Medium severity. CVSS v3 base score is 6.1 out of 10.
- Is CVE-2025-54800 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.