7.5

CVE-2025-54864: nixos hydra

CVSS: 7.5v3.1HighAnalyzed
Published 12-08-2025Last modified 12-08-2025
Open JSON

Vulnerability summary

CVE-2025-54864 is a high (CVSS 7.5) vulnerability in nixos hydra. EPSS estimates a 0.38% chance of exploitation in the next 30 days, higher than 30.8% of scored vulnerabilities.

Overall risk
30/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.5/10
010
High · v3.1 (NVD)
EPSS score
0.38%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 12-08-2025
    PublishedVulnerability first disclosed.
  2. 12-08-2025
    Last modifiedVulnerability information updated.

Description

Hydra is a continuous integration service for Nix based projects. Prior to commit f7bda02, /api/push-github and /api/push-gitea are called by the corresponding forge without HTTP Basic authentication. Both forges do however feature HMAC signing with a secret key. Triggering an evaluation can be very taxing on the infrastructure when large evaluations are done, introducing potential denial of service attacks on the host running the evaluator. This issue has been patched by commit f7bda02. A workaround involves blocking /api/push-github and /api/push-gitea via a reverse proxy.

CVSS metrics

3 scores · 2 sources · 2 versions

EPSS trend

Probability

0.38%

Chance of exploitation in the next 30 days

Percentile

31%

Versus all other CVEs

30-day change

0.00 pp

From 0.38% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.38%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Nixos1 product
  • hydra< f7bda020c6144913f134ec616783e57817f7686f | < 2025-08-12

1 vendor · 1 product

References

2 links