# CVE-2025-32435: Hydra no restricted eval after nix-eval-jobs migration

> Attackers can execute arbitrary code in Hydra to access secrets accessible by the hydra user, bypassing intended evaluation restrictions.

- **Severity:** Low 2.6 (`CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 15 Apr 2025
- **Updated:** 16 Apr 2025
- **Also known as:** GHSA-j7w7-965w-vjxw

## What is CVE-2025-32435?

CVE-2025-32435 is a low-severity code injection vulnerability in NixOS hydra, published on 15 Apr 2025. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

Hydra is a Continuous Integration service for Nix based projects. Evaluation of untrusted non-flake nix code could potentially access secrets that are accessible by the hydra user/group. This should not affect the signing keys, that are owned by the hydra-queue-runner and hydra-www users respectively.

Weakness: CWE-95 (Improper Neutralization of Directives in Dynamically Evaluated Code)

## Which versions are affected by CVE-2025-32435?

It affects 1 product.


Products: Nixos Hydra.

## How do I fix CVE-2025-32435?

No fix has been published for CVE-2025-32435 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-32435 being exploited?

There is no known exploitation of CVE-2025-32435 in the wild and no public exploit code.

## Other vulnerabilities in NixOS hydra

- [CVE-2024-45049](https://insights.sbomify.com/CVE-2024-45049/): Nix Hydra Missing authentication when triggering evaluations (high 7.5)
- [CVE-2025-54800](https://insights.sbomify.com/CVE-2025-54800/): Hydra persistent XSS in build metrics (high 7.1)
- [CVE-2025-54864](https://insights.sbomify.com/CVE-2025-54864/): Hydra missing authentication when triggering evaluations through GitHub and Gitea plugins (medium 6.9)
- [CVE-2024-32657](https://insights.sbomify.com/CVE-2024-32657/): Hydra has persistent XSS vulnerability serving HTML build outputs (medium 4.6)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-32435 and fix it if it is affected.

What it is: CVE-2025-32435 is a low-severity code injection vulnerability in NixOS hydra, published on 15 Apr 2025. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2025-32435 in the wild and no public exploit code.

Affected product: NixOS hydra. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-32435/ (Markdown: https://insights.sbomify.com/CVE-2025-32435/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-32435
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-32435
- OSV: https://osv.dev/vulnerability/CVE-2025-32435

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-32435/
Summaries are generated and may contain mistakes; the official description above is the record.