GHSA-pqm6-cgwr-x6pf is a high-severity (CVSS 8.8) CWE-347 vulnerability in robrichards/xmlseclibs. A fix is available for robrichards/xmlseclibs — see the affected versions and patch details below.
Signature validation bypass in XmlSecLibs
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-pqm6-cgwr-x6pf 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% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
robrichards/xmlseclibs🐘robrichards/xmlseclibsReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Rob Richards XmlSecLibs, all versions prior to v3.0.3, as used for example by SimpleSAMLphp, performed incorrect validation of cryptographic signatures in XML messages, allowing an authenticated attacker to impersonate others or elevate privileges by creating a crafted XML message.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | robrichards/xmlseclibs | ≥ 3.0.0&&< 3.0.4 | 3.0.4composer require robrichards/xmlseclibs:^3.0.4 |
| 🐘Packagist | robrichards/xmlseclibs | ≥ 1.0.0&&< 2.1.1 | 2.1.1composer require robrichards/xmlseclibs:^2.1.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for robrichards/xmlseclibs, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update robrichards/xmlseclibs to 3.0.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-pqm6-cgwr-x6pf 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-pqm6-cgwr-x6pf can be triaged on real exposure rather than presence alone.
Tailored to GHSA-pqm6-cgwr-x6pf. 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-pqm6-cgwr-x6pf in your dependencies?
O3 Security finds GHSA-pqm6-cgwr-x6pf across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.