GHSA-mh5m-5hw4-5c69
HIGHTinyMCE Cross-Site Scripting (XSS) vulnerability using sanitization bypass through nested SVGs
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
tinymcenpmDescription
Impact
TinyMCE 6.8.x contains an XSS vulnerability caused by improper SVG namespace scope handling in the sanitizer. A crafted payload using nested <svg> elements can bypass attribute sanitization and execute arbitrary JavaScript.
Patches
This issue affects TinyMCE 6.8.x-7.0.x. The vulnerability is fixed in TinyMCE 7.1.0 and later.
Workarounds
No official workaround available.
Acknowledgements
Tiny thanks maple3142 (https://maple3142.net) of DEVCORE for their help identifying this vulnerability.
References
Fix introduced in TinyMCE 7.1.0 though a rewrite of code causing the vulnerability.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | tinymce | ≥ 6.8.0&&< 7.1.0 | 7.1.0 |
| .NETNuGet | TinyMCE | ≥ 6.8.0&&< 7.1.0 | 7.1.0 |
| 🐘Packagist | tinymce/tinymce | ≥ 6.8.0&&< 7.1.0 | 7.1.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for tinymce. 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 tinymce to 7.1.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-mh5m-5hw4-5c69 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-mh5m-5hw4-5c69 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-mh5m-5hw4-5c69. 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-mh5m-5hw4-5c69 in your dependencies?
O3 detects GHSA-mh5m-5hw4-5c69 across npm, NuGet, Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.