How severe is CVE-2025-54864?

CVE-2025-54864 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2025-54864 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (31st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-54864?

CVE-2025-54864 affects Nixos Hydra. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-54864?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2025-54864 have an EU (EUVD) identifier?

Yes. CVE-2025-54864 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-24265.

When was CVE-2025-54864 published?

CVE-2025-54864 was published on 2025-08-12 and last updated on 2026-06-17.

CVE-2025-54864

CVE-2025-54864 is a high-severity vulnerability in Nixos Hydra with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-306.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 6.9
EPSS exploit prediction: 0% (31st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-24265
Weakness: CWE-306
Affected product: Nixos Hydra
Published: 2025-08-12
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2025-54864?: 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.
How severe is CVE-2025-54864?: CVE-2025-54864 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2025-54864 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (31st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-54864?: CVE-2025-54864 affects Nixos Hydra. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-54864?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2025-54864 have an EU (EUVD) identifier?: Yes. CVE-2025-54864 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-24265.
When was CVE-2025-54864 published?: CVE-2025-54864 was published on 2025-08-12 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:nixos:hydra:*:*:*:*:*:*:*:*

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