GHSA-jw9c-mfg7-9rx2 is a critical-severity (CVSS 10) CWE-347 vulnerability in ruby-saml. 2 public exploit references exist, so weaponization risk is real. A fix is available for ruby-saml — see the affected versions and patch details below.
SAML authentication bypass via Incorrect XPath selector
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-jw9c-mfg7-9rx2.
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.
How urgent is this, really
GHSA-jw9c-mfg7-9rx2 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,166 CVEs with a current EPSS score, this one falls in the 10–50% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
ruby-saml💎ruby-samlReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects RubyGems packages — download data is not available via public APIs for these ecosystems.
Description
Ruby-SAML in <= 12.2 and 1.13.0 <= 1.16.0 does not properly verify the signature of the SAML Response. An unauthenticated attacker with access to any signed saml document (by the IdP) can thus forge a SAML Response/Assertion with arbitrary contents. This would allow the attacker to log in as arbitrary user within the vulnerable system.
This vulnerability was reported by ahacker1 of SecureSAML ([email protected])
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💎RubyGems | ruby-saml | all versions | 1.12.3bundle update ruby-saml --conservative |
| 💎RubyGems | ruby-saml | ≥ 1.13.0&&< 1.17.0 | 1.17.0bundle update ruby-saml --conservative |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for ruby-saml, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update ruby-saml to 1.12.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-jw9c-mfg7-9rx2 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-jw9c-mfg7-9rx2 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-jw9c-mfg7-9rx2. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Frequently Asked Questions
Is GHSA-jw9c-mfg7-9rx2 in your dependencies?
O3 Security finds GHSA-jw9c-mfg7-9rx2 across RubyGems dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.