GHSA-4q66-g4mm-8rg5 is a medium-severity (CVSS 5.4) vulnerability in silverstripe/admin. A fix is available for silverstripe/admin — see the affected versions and patch details below.
Silverstripe has Cross-site Scripting (XSS) vulnerabilities inherited from TinyMCE
Real-World Exposure
silverstripe/adminReal-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
TinyMCE 4.x is vulnerable to several XSS vectors, which had been patched in later versions. Two of these have been identified as affecting silverstripe/admin.
Only Silverstripe CMS 4 is affected by this issue. It's not possible to upgrade Silverstripe CMS 4 to use a more recent release of TinyMCE without introducing breaking changes. Instead, the security patches that shipped in later releases of TinyMCE have been backported to the TinyMCE version bundled in silverstripe/admin.
Silverstripe CMS 5 is not affected by those vulnerabilities because it uses TinyMCE 6.
You can find more information about the underlying vulnerabilities in those GitHub security advisories:
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | silverstripe/admin | all versions | 1.13.6composer require silverstripe/admin:^1.13.6 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for silverstripe/admin, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update silverstripe/admin to 1.13.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-4q66-g4mm-8rg5 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-4q66-g4mm-8rg5 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-4q66-g4mm-8rg5. 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-4q66-g4mm-8rg5 in your dependencies?
O3 Security finds GHSA-4q66-g4mm-8rg5 across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.