CVE-2025-46551
lowpriority · track · 15EPSS 0.002 · 9 %ileEUUSEPSS · scored 2026-10-27
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.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–medium · 3.7–5.7
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (8)
Products and version ranges known to be affected.
advisories (1)
Vendor and ecosystem advisories describing this.
- GHSA-72qj-48g4-5xgxJRuby-OpenSSL has hostname verification disabled by default2025-05-07ghsa · osvUS
### Summary When verifying SSL certificates, jruby-openssl is not verifying that the hostname presented in the certificate matches the one we are trying to connect to, meaning a MITM could just present _any_ valid cert for a completely different domain they own, and JRuby wouldn't complain. ### Details n/a ### PoC An example domain bad.substitutealert.com was created to present the a certificate for the domain s8a.me. The following script run in IRB in CRuby 3.4.3 will fail with `certificate verify failed (hostname mismatch)`, but will work just fine in JRuby 10.0.0.0 and JRuby 9.4.2.0, both of which use jruby-openssl version 0.15.3 ```ruby require "net/http" require "openssl" uri = URI("https://bad.substitutealert.com/") https = Net::HTTP.new(uri.host, uri.port) https.use_ssl = true https.verify_mode = OpenSSL::SSL::VERIFY_PEER body = https.start { https.get(uri.request_uri).body } puts body ``` ### Impact Anybody using JRuby to make requests of external APIs, or scraping the web, that depends on https to connect securely
also known as (3)
Other names and identifiers for this entity.
sources
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references (9)
External citations — patches, advisories, analysis.
- https://access.redhat.com/security/cve/cve-2025-46551cnnvd
- https://github.com/jruby/jruby-openssl/commit/31a56d690ce9b8af47af09aaaf809081949ed285cnnvd
- https://github.com/jruby/jruby-openssl/security/advisories/GHSA-72qj-48g4-5xgxcnnvd
- https://vigilance.fr/vulnerability/JRuby-OpenSSL-Man-in-the-Middle-dated-14-07-2025-47699cnnvd
- https://www.jruby.org/Patchcnnvd
- https://github.com/jruby/jruby-openssl/commit/31a56d690ce9b8af47af09aaaf809081949ed285enisa_euvd
- https://github.com/jruby/jruby-openssl/security/advisories/GHSA-72qj-48g4-5xgxenisa_euvd
- https://github.com/jruby/jruby-openssl/commit/31a56d690ce9b8af47af09aaaf809081949ed285Patchnvd
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