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.

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)

EPSS: 0.002 (10.4th percentile) — read the EPSS interpretation.

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.

Affected products

Nixos Hydra — versions < dea1e168f590efb27db32dbacc82b09e15f8ae4b

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

Public proof-of-concept exploits

fkie-cad/nvd-json-data-feeds

References

security-advisories@github.com (x_refsource_CONFIRM, Patch, Vendor Advisory)
security-advisories@github.com (Patch, x_refsource_MISC)

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.