Silverstripe admin XSS Vulnerability via WYSIWYG editorGHSA-779c-7w4p-2c4g
LOWGHSA-779c-7w4p-2c4g is a low-severity (CVSS 3.8) vulnerability in silverstripe/admin. A fix is available for silverstripe/admin — see the affected versions and patch details below.
Real-World Exposure
silverstripe/admin🐘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
It is possible for a bad actor with access to the CMS to make use of onmouseover or onmouseout attributes in the WYSIWYG editor to embed malicious javascript.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | silverstripe/admin | ≥ 1.0.3&&< 1.0.4 | 1.0.4composer require silverstripe/admin:^1.0.4 |
| 🐘Packagist | silverstripe/admin | ≥ 1.1.0&&< 1.1.1 | 1.1.1composer require silverstripe/admin:^1.1.1 |
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 1.0.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-779c-7w4p-2c4g 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.
Frequently Asked Questions
Is GHSA-779c-7w4p-2c4g in your dependencies?
Find it across Packagist, including transitive dependencies.