GHSA-45qg-252v-3f7p

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 — an SVG script reports `"script"`, not `"SCRIPT"` — 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 interim.

### Credit

Reported by Roman Kis (@CrownKingClown).