PYSEC-2026-1905

### Summary In the `/license/` endpoint, the detailed view key is not properly validated and sanitized, which can result in a potential cross-site scripting (XSS) vulnerability when attempting to access a detailed license view that does not exist.

### Details In the `/license/` endpoint, the `license_details_view` function is vulnerable to a potential cross-site scripting (XSS) attack due to inadequate validation and sanitization of the `key` parameter. This vulnerability arises when attempting to access a key with malicious javascript.

```python def license_details_view(request, key): """ Display all available information about a given license `key` followed by the full license text. """ licenses = get_licenses() try: data = saneyaml.dump(licenses[key].to_dict()) text = licenses[key].text except KeyError: return HttpResponseNotFound(f"License {key} not found.") # Leads to cross-site scripting when key is malicious javascript return HttpResponse(f"<pre>{data}</pre><hr><pre>{text}</pre>") ```

### PoC 1. Access following endpoint on scancode.io instance: http://localhost/license/%3Cscript%3Ealert(document.cookie);%3C/script%3E/

### Impact Attackers can exploit the vulnerability to inject malicious scripts into the response generated by the `license_details_view` function. When unsuspecting users visit the page, their browsers will execute the injected scripts, leading to unauthorized actions, session hijacking, or stealing sensitive information.