You'll noticeTier: how much it should matter to you
2Useful: my rating, 1 to 5
2Signal: worth watching, 1 to 5
MCPArea: what it touches
ImprovementsKind: in v2.1.318,
ImprovementsSection of the release
What
Two changes affect how the managed deniedMcpServers and allowedMcpServers settings are matched against MCP servers. MCP servers are outside tools Claude Code connects to.
deniedMcpServers: a serverUrl entry now also blocks a server when it matches the address inside that server's mcp_url parameter. Before, only the address the server actually connects to was checked. Claude Code shows a warning saying the server is blocked because of this match.
allowedMcpServers: when a server could be described by more than one command, every one of those commands now has to match an allowed entry, not just one.
Why
This closes a way around an organization's deny list, where the blocked address could be wrapped inside another URL. Some servers that worked before may now be blocked.
