Two high-severity CVEs land in rmcp, the official Rust MCP SDK: OAuth token theft and a permanent session-table leak

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GitHub published CVE-2026-63127 (CVSS 8.2) and CVE-2026-63128 (CVSS 7.5) against the rmcp crate on 16 Sep 2026, both fixed in 2.0.0. The first is a missing `resource` field check in OAuth Protected Resource metadata discovery (RFC 9728 §3.3 and §7.3 are both MUST requirements), letting a malicious MCP server redirect the OAuth flow to a legitimate authorization server and steal the resulting access token. The second leaks one `LocalSessionHandle` per malformed JSON-RPC POST because `handle_post` allocates the session before validating the body; the reproduction sustains 2,000 leak requests per second, roughly 170 million entries and 75 GB of resident memory per day.