CVE-2026-48015: Shopware: Stored XSS via SVG file upload — no SVG sanitization SVG files are in the `allowed_extensions` whitelist and can be uploaded by any admin user via…

Shopware: Stored XSS via SVG file upload — no SVG sanitization

SVG files are in the `allowed_extensions` whitelist and can be uploaded by any admin user via the media manager. There is zero SVG content sanitization anywhere in the upload pipeline. A malicious SVG with JavaScript (`onload`, ``, ``) executes in the context of the Shopware domain when accessed.

## The Problem

In `src/Core/Framework/Resources/config/packages/shopware.yaml`, line 194:

```yaml
allowed_extensions: ["jpg", "jpeg", "png", "webp", "avif", "gif", "svg", ...]
```

SVG is whitelisted. The upload path (`MediaUploadController` → `FileSaver` → `TypeDetector`) recognizes SVG as `ImageType` with `VECTOR_GRAPHIC` flag, but no code strips JavaScript, event handlers, or external entity references from the SVG XML.

A search of the entire codebase for SVG sanitization returns — no `DOMPurify`, no `svg-sanitize`, no `strip_tags` on SVG content, nothing.

## Impact

Stored XSS affecting all users who view the uploaded SVG. In an e-commerce context, this can lead to admin account takeover, customer data theft, or malicious plugin installation.

## Suggested Fix

Either:

1. **Remove SVG from `allowed_extensions`** if SVG upload is not a core requirement
2. **Sanitize SVG content** on upload using a library like `enshrined/svg-sanitize` (strips scripts, event handlers, external references)
3. **Serve SVGs with `Content-Disposition: attachment`** to prevent inline rendering
4. **Serve SVGs from a separate domain** (like Nextcloud's `usercontent.apps.nextcloud.com`)

Option 2 is the most practical — `enshrined/svg-sanitize` is already used by WordPress and other PHP projects.

Regards & BG,
Keyvan Hardani

Affected