High · CVSS 7.4CVE-2025-0306

Ruby: openssl: ruby marvin attackCVE-2025-0306

Answer in brief

CVE-2025-0306 records a High severity (CVSS 7.4) vulnerability in Ruby: openssl: ruby marvin attack. The current sources do not mark it as known exploited. The current feed maps Ruby (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Jan 9, 2025Updated Jun 30, 2026Source checked Nov 3, 2026First seen by HOL Jun 25, 2026Material review Jun 30, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 7.4
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 7.4. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Ruby (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Rubygeneric	>=0 <*	*

Recommended response

Check inventory. Check lockfiles and deployed manifests for Ruby.
Review the reported fix. Source-reported workaround: See the following possible mitigations for this flaw: * Do not use the methods with PKCS#1v1.5 padding in network contexts. Make sure that any calls that happen, will perform OAEP decryption only. Do not support PKCS#1v1.5 encryption padding at all. * Use Ruby with a version of OpenSSL that has the implicit rejection mechanism implemented.(https://github.com/openssl/openssl/pull/13817, https://github.com/openssl/openssl/commit/7fc67e0a33102aa47bbaa56533eeecb98c0450f7 included in 3.2.0, backported to RHEL-8)

Evidence timeline and material changes

Published upstream
Jan 9, 2025
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Jun 30, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Jun 25, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.

Package

Affected range

Fixed version

Rubygeneric

>=0 <*

Recommended response

Check inventory. Check lockfiles and deployed manifests for Ruby.

Review the reported fix. Source-reported workaround: See the following possible mitigations for this flaw: * Do not use the methods with PKCS#1v1.5 padding in network contexts. Make sure that any calls that happen, will perform OAEP decryption only. Do not support PKCS#1v1.5 encryption padding at all. * Use Ruby with a version of OpenSSL that has the implicit rejection mechanism implemented.(https://github.com/openssl/openssl/pull/13817, https://github.com/openssl/openssl/commit/7fc67e0a33102aa47bbaa56533eeecb98c0450f7 included in 3.2.0, backported to RHEL-8)

Sources and claim methodology

Upstream source description

Quoted source text, attributed separately from HOL analysis.