Jodit Editor is a WYSIWYG editor with a built-in file browser & image editor. Prior to 4.13.6, Jodit's clean-html denyTags filter does not normalize foreign SVG or MathML script node names, allowing a script element nested directly in SVG or MathML to remain in editor.value and execute when content is loaded. This issue is fixed in version 4.13.6.
Affected: npm: jodit
A `<script>` element placed directly inside an `<svg>` (or MathML) container was not removed by Jodit's clean-html sanitizer.
The deny/allow tag filter compared `node.nodeName` against an upper-cased tag hash, but foreign (SVG/MathML) elements preserve their original-case node names β an SVG script reports `"script"`, not `"SCRIPT"` β so the default `denyTags` list (which includes `script`) did not match it. The script therefore survived in the editor value and serialized output, where it could execute when the content was loaded back into a page or editor.
### Proof of concept
```html <svg xmlns="http://www.w3.org/2000/svg" width="400" height="400" viewBox="0 0 124 124"> <rect width="124" height="124" rx="24" fill="#000000"></rect> <script type="text/javascript">alert(document.domain);</script> </svg> ```
Load the payload into the editor (e.g. via source mode) and the `<script>` is preserved in `editor.value` and executes.
### Impact
Stored / DOM cross-site scripting. An application that persists editor output and later renders or re-opens it in Jodit can have attacker-supplied script run in a victim's (e.g. an administrator's) authenticated browser context.
### Patch
Fixed in **4.13.6**: the deny/allow lookup now normalises the tag name to upper case before matching, so a foreign namespace can no longer bypass the filter, while `allowTags` is still honoured.
### Workaround
Upgrade to 4.13.6 or later. Server-side sanitization of stored HTML mitigates in the inβ¦