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TI-2025-34554 Aliases CVE-2025-54800

Hydra persistent XSS in build metrics

Priority LOW 31CWE-79Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Passive
Attack complexity
Low
Attack requirements
None
Impact type
Cross-site scripting
Confidentiality · integrity · availability
Low · High · None
Fix status
No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-79.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00214 11th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
NixOShydra< dea1e168f590efb27db32dbacc82b09e15f8ae4b—No fix listedCNA
  • hydra VendorNixOS Affected < dea1e168f590efb27db32dbacc82b09e15f8ae4b Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:nixos:hydra:*:*:*:*:*:*:*:*before 2025-08-12VulnerableNixOS
  • cpe:2.3:a:nixos:hydra:*:*:*:*:*:*:*:* Versions before 2025-08-12 Vulnerable ·NixOS

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2025-54800

References

Patch 2

  • TI-2024-30161 Nix Hydra Missing authentication when triggering evaluations CVSS 3.1HIGH 7.5
  • TI-2025-34598 Hydra missing authentication when triggering evaluations through GitHub and Gitea plugins CVSS 4.0MEDIUM 6.9
  • TI-2024-21538 Hydra has persistent XSS vulnerability serving HTML build outputs CVSS 3.1MEDIUM 5.4
  • TI-2025-23506 Hydra no restricted eval after nix-eval-jobs migration CVSS 3.1LOW 2.6

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences