Hands-on MCP security, one problem at a time
October 12, 2026 · Granthinge
Audience validation only matters if the signature check underneath it is sound. How an MCP server fetches and caches signing keys, survives a key rotation, pins algorithms, and decides between local JWT validation and introspection.
Read moreOctober 5, 2026 · Granthinge
What to do in the first hour after an MCP server incident: contain the tokens, read the audit trail, meet the notification clock, and keep the directory listing.
Read moreSeptember 28, 2026 · Granthinge
Protocol revision 2026-07-28 removes sessions and the initialize handshake. Here is what that does to handle binding, retry authorization, and the audit fields a reviewer already saw.
Read moreSeptember 21, 2026 · Granthinge
The MCP Apps extension lets a tool return an interactive interface instead of text. It also puts your HTML inside the host, talking back over postMessage. Here is what a reviewer will ask about that, and what the server has to enforce.
Read moreSeptember 21, 2026 · Granthinge
When authorization rules stop fitting in handler code, the answer is a policy decision point. Here is when to externalize MCP tool authorization, what the interface looks like, and what it costs.
Read more