CVE-2026-44429— MCP Registry: Stored XSS in catalogue UI via attribute-quote breakout in publisher-controlled `websiteUrl`

MCP Registry: Stored XSS in catalogue UI via attribute-quote breakout in publisher-controlled `websiteUrl`

The MCP Registry provides MCP clients with a list of MCP servers, like an app store for MCP servers. Prior to 1.7.7, the public catalogue UI served at GET / (file internal/api/handlers/v0/ui_index.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 URL parses, is absolute, and uses the https scheme; it does not reject quote characters. Client-side, the value is interpolated into a double-quoted href attribute via innerHTML, using a homegrown escapeHtml helper that performs the standard textContent → innerHTML round-trip. Per the HTML serialisation algorithm, that round-trip encodes only &, <, > and U+00A0 inside text nodes — it does not encode " or '. A literal " in websiteUrl therefore breaks out of the href attribute, allowing arbitrary on* event handlers to be appended to the same <a> element. The Content-Security-Policy on / is script-src 'self' 'unsafe-inline' https://cdn.tailwindcss.com, so the injected event handlers execute. Any user able to obtain a publish token (e.g. via POST /v0/auth/github-at with their own GitHub account, or POST /v0/auth/none on a deployment that has anonymous auth enabled) can plant a poisoned record visible to every visitor of the registry homepage. This vulnerability is fixed in 1.7.7.

N/A

在Web页面生成时对输入的转义处理不恰当(跨站脚本)

MCP Registry 跨站脚本漏洞

MCP Registry是Model Context Protocol开源的一个MCP服务器应用商店。 MCP Registry 1.7.7之前版本存在跨站脚本漏洞，该漏洞源于公共目录UI，服务器端验证仅检查URL是否可解析、绝对且使用https方案，未拒绝引号字符，客户端通过innerHTML将值插值到双引号href属性中，escapeHtml助手未编码引号，导致攻击者可注入任意事件处理程序。

N/A

N/A