GHSA-RQV2-M695-F8J4 MCP Registry vulnerable to stored XSS in catalogue UI via attribute-quote breakout in publisher-controlled `websiteUrl`

Summary The public catalogue UI served at GET / file internal/api/handlers/v0/uiindex.html is vulnerable to stored cross-site scripting via the server.websiteUrl field of any published server.json. Server-side validation in internal/validators/validators.go validateWebsiteURL only checks that the...