GHSA-6hjc-m38h-7jhh
MEDIUMGHSA-6hjc-m38h-7jhh is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in nystudio107/craft-seomatic. O3 Security confirms whether GHSA-6hjc-m38h-7jhh is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Cross-site Scripting in SEOmatic plugin
Blast Radius
nystudio107/craft-seomaticReal-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
A cross-site scripting (XSS) vulnerability in the SEOmatic plugin 3.4.10 for Craft CMS 3 allows remote attackers to inject arbitrary web script via a GET to /index.php?action=seomatic/file/seo-file-link with url parameter containing the base64 encoded URL of a malicious web page / file and fileName parameter containing an arbitrary filename with the intended content-type to be rendered in the user's browser as the extension.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | nystudio107/craft-seomatic | all versions | 3.4.11 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for nystudio107/craft-seomatic. 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 nystudio107/craft-seomatic to 3.4.11 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-6hjc-m38h-7jhh 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-6hjc-m38h-7jhh 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-6hjc-m38h-7jhh. 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-6hjc-m38h-7jhh in your dependencies?
O3 detects GHSA-6hjc-m38h-7jhh across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.