Summary
SilverStripe CMS Cross-site Scripting vulnerabilities inherited from TinyMCE
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 these vulnerabilities. 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 these vulnerabilities because it uses TinyMCE 6.
Impact
Untrusted input is rendered as active markup in a victim's browser, which can run script in their session. Typical impact: session or credential theft, and actions taken as the user.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is GHSA-JXCX-3H54-QQXX? GHSA-JXCX-3H54-QQXX is a medium-severity cross-site scripting (XSS) vulnerability in silverstripe/admin (composer), affecting versions >= 1.0.0, < 1.13.6. It is fixed in 1.13.6. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.
- Which versions of silverstripe/admin are affected by GHSA-JXCX-3H54-QQXX? silverstripe/admin (composer) versions >= 1.0.0, < 1.13.6 is affected.
- Is there a fix for GHSA-JXCX-3H54-QQXX? Yes. GHSA-JXCX-3H54-QQXX is fixed in 1.13.6. Upgrade to this version or later.
- Is GHSA-JXCX-3H54-QQXX exploitable, and should I be worried? Whether GHSA-JXCX-3H54-QQXX is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether GHSA-JXCX-3H54-QQXX is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix GHSA-JXCX-3H54-QQXX? Upgrade
silverstripe/adminto 1.13.6 or later.