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fix(mcp): reject invalid JSON-RPC ids before dispatch (#391) #430

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fix(mcp): reject invalid JSON-RPC ids before dispatch (#391) #430

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debd29a
fix(mcp): reject invalid JSON-RPC ids before stdio/SSE dispatch (#391)
MatrixAdventurer Nov 11, 2026
eb56620
fix(api): reject malformed JSON-RPC ids before HTTP dispatch (#391)
MatrixAdventurer Nov 11, 2026
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10 changes: 10 additions & 0 deletions memoria/crates/memoria-api/src/routes/mcp.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -260,6 +260,16 @@ pub async fn mcp_handler(
);
}

// Reject non-conforming IDs before ping, notification, or tool dispatch.
if req.get("id").is_some_and(|id| !(id.is_string() || id.is_number() || id.is_null())) {
validation_err!(
"/mcp/_invalid_request",
-32600,
json!({"jsonrpc": "2.0", "id": null,
"error": {"code": -32600, "message": "Invalid Request: id must be string, number or null"}})
);
}

// "jsonrpc" MUST equal exactly "2.0".
if req.get("jsonrpc").and_then(|v| v.as_str()) != Some("2.0") {
let id = req.get("id").cloned().unwrap_or(serde_json::Value::Null);
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5 changes: 3 additions & 2 deletions memoria/crates/memoria-mcp/src/server.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -264,7 +264,7 @@ fn sse_router(
// payloads still need an Invalid Request response, even without id.
// Preserve the legacy endpoint's jsonrpc-field compatibility here;
// tightening envelope validation is separate from notification handling.
if !req.is_object() || method.is_empty() {
if !req.is_object() || method.is_empty() || req.get("id").is_some_and(|id| !(id.is_string() || id.is_number() || id.is_null())) {
let response_id = req.get("id").filter(|id| id.is_string() || id.is_number()).cloned().unwrap_or(Value::Null);
let resp = serde_json::json!({"jsonrpc":"2.0","id":response_id,
"error":{"code":-32600,"message":"Invalid Request"}});
Expand Down Expand Up @@ -354,8 +354,9 @@ async fn run_io(
.cloned()
.unwrap_or(Value::Null);
let is_object = value.is_object();
let valid_id = value.get("id").is_none_or(|id| id.is_string() || id.is_number() || id.is_null());
let req = match serde_json::from_value::<Request>(value) {
Ok(req) if is_object && !req.method.is_empty() => req,
Ok(req) if is_object && valid_id && !req.method.is_empty() => req,
_ => {
let resp = json!({"jsonrpc":"2.0","id":response_id,
"error":{"code":-32600,"message":"Invalid Request"}});
Expand Down
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