medium5.7
CVE-2026-44427
The MCP Registry provides MCP clients with a list of MCP servers, like an app store for MCP servers.
Impact
The MCP Registry provides MCP clients with a list of MCP servers, like an app store for MCP servers. From 1.1.0 to 1.7.4, the TrailingSlashMiddleware in internal/api/server.go is vulnerable to an open redirect attack. An attacker can craft a URL with a protocol-relative path (e.g., //evil.com/) that, after trailing slash removal, results in a Location header of //evil.com — which browsers interpret as an absolute URL to an external domain. This vulnerability is fixed in 1.7.5.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| go | github.com/modelcontextprotocol/registry | >= 1.1.0, < 1.7.5 | 1.7.5 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-v8vw-gw5j-w7m6
- https://github.com/modelcontextprotocol/registry/security/advisories/GHSA-v8vw-gw5j-w7m6
- https://github.com/modelcontextprotocol/registry/pull/1227
- https://github.com/modelcontextprotocol/registry/commit/1201cbd82b2cf6d4b56edfc05c763059a12f9fdb
- https://github.com/modelcontextprotocol/registry/releases/tag/v1.7.5
- https://nvd.nist.gov/vuln/detail/CVE-2026-44427