Using a colon (:) as a delimiter for concatenating multiple fields in the cache key can lead to potential cache key collisions if any of the fields (such as reqCtx.Protocol or reqCtx.Target) contain colons. Since reqCtx.Target is derived from the user-controlled authFrame.TargetService, a malicious client could craft a target service name containing colons to collide with another cached authorization entry.

To prevent delimiter collision attacks, use a null byte (\x00) as the separator, as it cannot legitimately appear in standard protocol names or target services.

The newly introduced startUnauthSidecarServer initializes an http.Server without setting any timeouts (ReadTimeout, WriteTimeout, IdleTimeout). This leaves the server vulnerable to Slowloris attacks and resource exhaustion. It is highly recommended to configure reasonable timeouts.

	server := &http.Server{
		Handler:      mux,
		ReadTimeout:  5 * time.Second,
		WriteTimeout: 10 * time.Second,
		IdleTimeout:  120 * time.Second,
	}

In fetchRemoteResourceCatalogue, there is no check to ensure that the resource pointer r is not nil. If a remote peer returns a list containing null elements, this will cause a nil pointer dereference panic, crashing the node. We should add a defensive nil check.

		listRes, err := session.ListResources(ctx, &mcp.ListResourcesParams{})
		if err == nil && listRes != nil {
			for _, r := range listRes.Resources {
				if r == nil {
					continue
				}
				// Namespace the URI scheme or name if we want, but resources are URIs.
				// We'll prefix the Name to indicate origin.
				r.Name = svc.Name + "." + r.Name
				allResources = append(allResources, r)
			}
		}

In fetchRemotePromptCatalogue, there is no check to ensure that the prompt pointer p is not nil. If a remote peer returns a list containing null elements, this will cause a nil pointer dereference panic, crashing the node. We should add a defensive nil check.

		listRes, err := session.ListPrompts(ctx, &mcp.ListPromptsParams{})
		if err == nil && listRes != nil {
			for _, p := range listRes.Prompts {
				if p == nil {
					continue
				}
				p.Name = svc.Name + "." + p.Name
				allPrompts = append(allPrompts, p)
			}
		}

In handleReadRemoteResource, defer cleanup() is used inside a for loop. In Go, defer statements are evaluated when the surrounding function returns, not when the loop block ends. Although the function returns immediately in this branch, using defer inside a loop is a known anti-pattern and can lead to resource leaks if the code is refactored in the future to not return immediately. It is cleaner and safer to call cleanup() directly.

The output of find_remote_tools is a JSON array of tool objects, not an object containing an items key. Using .items[]? in the jq filter will result in an empty string, causing the E2E test to fail to discover the tool and eventually timeout. It should be updated to use .[]? instead.

The hubAddr variable is registered with a default value of DefaultHubURL ("http://localhost:8080"), meaning displayHub will never be empty under normal execution. As a result, the fallback block to load the stored hub URL or default to the public bananas mesh will never be executed. Consider checking if displayHub is equal to DefaultHubURL or empty.