fix(mcp): guard nil initializeParams on new-protocol notifications#1047
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kuangmi-bit wants to merge 1 commit into
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fix(mcp): guard nil initializeParams on new-protocol notifications#1047kuangmi-bit wants to merge 1 commit into
kuangmi-bit wants to merge 1 commit into
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When a JSON-RPC notification (id: null) carries new-protocol _meta (protocolVersion >= 2026-07-28), validateRequestMeta returns usesNewProtocol=true with initializeParams=nil — notifications do not carry client identity per SEP-2575. The per-request protocol version check at server.go:1816 then dereferenced initializeParams without a nil guard, causing a panic. Fix: add validatedMeta.initializeParams != nil guard before accessing .ProtocolVersion. Notifications skip the version check entirely (same guard pattern already used at line 1846 for init state). Adds regression test: notification with new-protocol _meta must not panic and must return without error. Fixes modelcontextprotocol#1043 Fixes modelcontextprotocol#1046
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What
Fixes a panic in the server-side per-request protocol metadata path when a JSON-RPC notification (
id: null) carries new-protocol_meta(protocolVersion >= 2026-07-28).Root cause
validateRequestMeta(§2.3 step 3) returnsusesNewProtocol=truewithinitializeParams=nilfor notifications — notifications do not carry client identity per SEP-2575. The protocol version check atserver.go:1816then dereferencedinitializeParams.ProtocolVersionwithout a nil guard.Fix
Add
validatedMeta.initializeParams != nilguard before accessing.ProtocolVersion. Notifications skip the version check entirely — the same guard pattern already used at line 1846 for initialization state.Regression test
TestServerSessionHandle_NewProtocolNotificationWithoutParamssends anotifications/cancellednotification with new-protocol_metaand verifies it returns without error (no panic).Related
Fixes #1043
Fixes #1046