# CVE-2025-0306: Ruby: openssl: ruby marvin attack

> Attackers can decrypt messages or forge signatures via the Marvin Attack against Ruby's OpenSSL implementation, compromising data confidentiality and integrity.

- **Severity:** High 7.4 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 9 Jan 2025
- **Updated:** 29 Jun 2026
- **Also known as:** AZL-110513, DEBIAN-CVE-2025-0306, GHSA-vvxp-46w2-6p8r

## What is CVE-2025-0306?

CVE-2025-0306 is a high-severity vulnerability in Red Hat Enterprise Linux 10, published on 9 Jan 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability was found in Ruby. The Ruby interpreter is vulnerable to the Marvin Attack. This attack allows the attacker to decrypt previously encrypted messages or forge signatures by exchanging a large number of messages with the vulnerable service.

Weakness: CWE-385 (Covert Timing Channel)

## Which versions are affected by CVE-2025-0306?


## How do I fix CVE-2025-0306?

No fix has been published for CVE-2025-0306 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-0306 being exploited?

There is no known exploitation of CVE-2025-0306 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-0306 and fix it if it is affected.

What it is: CVE-2025-0306 is a high-severity vulnerability in Red Hat Enterprise Linux 10, published on 9 Jan 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-0306 in the wild and no public exploit code.

Affected product: Red Hat Enterprise Linux 10. 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-2025-0306/ (Markdown: https://insights.sbomify.com/CVE-2025-0306/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-0306
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-0306
- OSV: https://osv.dev/vulnerability/CVE-2025-0306

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-0306/
Summaries are generated and may contain mistakes; the official description above is the record.