PYSEC-2026-1276

copyparty Reflected XSS via Filter Parameter

### Summary Unauthorized reflected Cross-Site-Scripting when accessing the URL for recent uploads with the `filter` parameter containing JavaScript code. ### Details When accessing the recent uploads page at `/?ru`, users can filter the results using an input field at the top. This field appends a filter parameter to the URL, which reflects its value directly into a `<script>` block without proper escaping. This vulnerability allows for reflected Cross-Site Scripting (XSS) and can be exploited against both authenticated and unauthenticated users, enabling unwanted actions in the victims browser. ### PoC A URL like this will execute `alert(1)`: ``` https://127.0.0.1:3923/?ru&filter=</script><script>alert(1)</script> ```