GHSA-xmxj-v2q8-8qx6 is a low-severity (CVSS 2.4) Cross-site Scripting (XSS) vulnerability in concrete5/concrete5. O3 Security confirms whether GHSA-xmxj-v2q8-8qx6 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Concrete CMS Stored XSS in the "Next&Previous Nav" block
Real-World Exposure
concrete5/concrete5🐘concrete5/concrete5Real-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
Concrete CMS versions 9.0.0 to 9.3.4 and below 8.5.19 are vulnerable to Stored XSS in the "Next&Previous Nav" block. A rogue administrator could add a malicious payload by executing it in the browsers of targeted users. Since the "Next&Previous Nav" block output was not sufficiently sanitized, the malicious payload could be executed in the browsers of targeted users.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | concrete5/concrete5 | all versions | 8.5.19 |
| 🐘Packagist | concrete5/concrete5 | ≥ 9.0.0&&< 9.3.4 | 9.3.4 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for concrete5/concrete5. 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 concrete5/concrete5 to 8.5.19 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-xmxj-v2q8-8qx6 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-xmxj-v2q8-8qx6 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-xmxj-v2q8-8qx6. 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-xmxj-v2q8-8qx6 in your dependencies?
O3 detects GHSA-xmxj-v2q8-8qx6 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.