GHSA-72qj-48g4-5xgx
JRuby-OpenSSL has hostname verification disabled by default
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
rubygems:jruby-openssl☕org.jruby:jruby☕org.jruby:jruby💎jruby-opensslReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
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
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
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | rubygems:jruby-openssl | ≥ 0.12.1&&< 0.15.4 | 0.15.4 |
| ☕Maven | org.jruby:jruby | ≥ 10.0.0.0&&< 10.0.0.1 | 10.0.0.1 |
| ☕Maven | org.jruby:jruby | ≥ 9.3.4.0&&< 9.4.12.1 | 9.4.12.1 |
| 💎RubyGems | jruby-openssl | ≥ 0.12.1&&< 0.15.4 | 0.15.4 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for rubygems:jruby-openssl. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update rubygems:jruby-openssl to 0.15.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-72qj-48g4-5xgx is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-72qj-48g4-5xgx is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-72qj-48g4-5xgx. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-72qj-48g4-5xgx in your dependencies?
O3 detects GHSA-72qj-48g4-5xgx across Maven, RubyGems dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.