JRuby-openssl up to 0.15.3 on JRuby certificate validation

Summaryinfo

A vulnerability was found in JRuby-openssl up to 0.15.3 on JRuby. It has been classified as critical. The impacted element is an unknown function. Performing a manipulation results in certificate validation. This vulnerability is cataloged as CVE-2025-46551. It is possible to initiate the attack remotely. There is no exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability classified as critical has been found in JRuby-openssl up to 0.15.3 on JRuby. This affects an unknown code block. The manipulation with an unknown input leads to a certificate validation vulnerability. CWE is classifying the issue as CWE-295. The product does not validate, or incorrectly validates, a certificate. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

JRuby-OpenSSL is an add-on gem for JRuby that emulates the Ruby OpenSSL native library. Starting in JRuby-OpenSSL version 0.12.1 and prior to version 0.15.4 (corresponding to JRuby versions starting in 9.3.4.0 prior to 9.4.12.1 and 10.0.0.0 prior to 10.0.0.1), when verifying SSL certificates, JRuby-OpenSSL does not verify that the hostname presented in the certificate matches the one the user tries to connect to. This means a man-in-the-middle could just present any valid cert for a completely different domain they own, and JRuby would accept the cert. Anybody using JRuby to make requests of external APIs, or scraping the web, that depends on https to connect securely. JRuby-OpenSSL version 0.15.4 contains a fix for the issue. This fix is included in JRuby versions 10.0.0.1 and 9.4.12.1.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2025-46551 since 04/24/2025. The exploitability is told to be difficult. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 10/22/2025). MITRE ATT&CK project uses the attack technique T1587.003 for this issue.

The vulnerability scanner Nessus provides a plugin with the ID 264336 (Linux Distros Unpatched Vulnerability : CVE-2025-46551), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 0.15.4 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (264336). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Network Encryption Software

Name

• JRuby-openssl

Version

• 0.15.0
• 0.15.1
• 0.15.2
• 0.15.3

Support

• end of life (old version)

CPE 2.3info

• 🔍
• 🔍
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CPE 2.2info

• 🔍
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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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