Issues

• Security best practices: SSRF section does not cover local stdio-to-HTTP bridges acting as OAuth clients

  modelcontextprotocol/modelcontextprotocol#3437 · Filter by author playb0t opened on Oct 15, 2026

• Docs: quickstart MCP configs use unpinned npx -y, contradicting the Local Server Security guide

  modelcontextprotocol/modelcontextprotocol#3431 · Filter by author basitalisandhu opened on Oct 13, 2026
  3

• [Spec & Ecosystem] Lack of enforced Server-level routing descriptions breaks LLM tool selection under Lazy/Deferred Loading (especially when paired with Agent Skills)

  bug
  modelcontextprotocol/modelcontextprotocol#3430 · Filter by author xujiawen8610 opened on Oct 13, 2026

• Client-credentials examples should require issuer binding

  modelcontextprotocol/modelcontextprotocol#3419 · Filter by author LHMisme420 opened on Oct 6, 2026
  1

• Docs: clarify where an MCP server should integrate in an existing application architecture

  modelcontextprotocol/modelcontextprotocol#3417 · Filter by author peter-iglaev opened on Oct 6, 2026
  1

• Access Token Privilege Restriction: does "MUST NOT pass through" cover an API of the same authorization server/project (Supabase Edge MCP pattern)?

  modelcontextprotocol/modelcontextprotocol#3413 · Filter by author jryski opened on Oct 4, 2026
  5

• Lost-response retry on a mutating tools/call re-executes external effects — reproduction evidence and a spec-clarification question

  modelcontextprotocol/modelcontextprotocol#3394 · Filter by author arjun2075 opened on Sep 27, 2026
  25

• Origin validation rejects browser-based MCP clients on authenticated remote servers

  bug
  modelcontextprotocol/modelcontextprotocol#3370 · Filter by author daoluc opened on Sep 18, 2026
  7

• Security considerations section can be improved

  bug
  modelcontextprotocol/modelcontextprotocol#3361 · Filter by author loganaden opened on Sep 14, 2026
  1

• cancellation.mdx and subscriptions.mdx disagree on how a server ends a subscriptions/listen stream

  modelcontextprotocol/modelcontextprotocol#3348 · Filter by author AmirK-S opened on Sep 6, 2026
  1

• inputSchema and requestedSchema hard-code JSON Schema keywords into dialect-agnostic slots

  bug
  modelcontextprotocol/modelcontextprotocol#3238 · Filter by author clemensv opened on Aug 14, 2026
  1

• Tasks extension (SEP-2663): no interoperable surface for partial output of a running task

  modelcontextprotocol/modelcontextprotocol#3237 · Filter by author Cam10001110101 opened on Aug 14, 2026

• Clarify whether notifications/resources/list_changed should be sent if the list of resource templates changes

  bug
  modelcontextprotocol/modelcontextprotocol#3226 · Filter by author mkouba opened on Aug 11, 2026

• generate:schema:json produces empty schemas when using wildcard type on Windows

  bug
  modelcontextprotocol/modelcontextprotocol#3114 · Filter by author vortsghost2025 opened on Jul 22, 2026
  1

• [Spec Gap] Tool Execution Errors lack a schema-governed signal for LLM forwarding — structuredContent should be defined for error path

  bug
  modelcontextprotocol/modelcontextprotocol#3003 · Filter by author antara1414 opened on Jul 2, 2026
  10

• SEP-2549: clarify whether cacheScope is required or defaults to public

  bug
  modelcontextprotocol/modelcontextprotocol#2939 · Filter by author DaleSeo opened on Jun 18, 2026
  

• MCP protocol lacks a mechanism for tools to stream incremental results

  modelcontextprotocol/modelcontextprotocol#2932 · Filter by author fy2ne opened on Jun 16, 2026
  9

• MRTR url-mode: standardize the "still waiting" response (state-only InputRequiredResult) + retry/cancel guidance

  modelcontextprotocol/modelcontextprotocol#2920 · Filter by author ferentinai opened on Jun 15, 2026
  1

• MRTR: inputRequests is a closed enum of three methods — add an extensible / reverse-DNS-namespaced member type

  modelcontextprotocol/modelcontextprotocol#2919 · Filter by author ferentinai opened on Jun 15, 2026
  3

• SDK feedback: oneOf in tool inputSchema isn't practically consumable by tool-calling LLMs

  modelcontextprotocol/modelcontextprotocol#2806 · Filter by author hypeprinter007-stack opened on May 27, 2026
  1

  

• SEP-2352 Clarification

  documentationsdk/2026-07-feedback
  modelcontextprotocol/modelcontextprotocol#2748 · Filter by author guglielmo-san opened on May 19, 2026
  2

• No visibility of errors from tool call responses

  bug
  modelcontextprotocol/modelcontextprotocol#2734 · Filter by author rlb567 opened on May 16, 2026
  8

• Clarify behavior when initialize.params.protocolVersion conflicts with MCP-Protocol-Version

  bug
  modelcontextprotocol/modelcontextprotocol#2721 · Filter by author cclabadmin opened on May 13, 2026

• Schema generation pipeline may produce overly permissive schemas without safeguards

  bug
  modelcontextprotocol/modelcontextprotocol#2600 · Filter by author httpsVishu opened on Apr 18, 2026
  2

• SDK Tiering - 'Task' issues should be out of scope for triage SLAs

  modelcontextprotocol/modelcontextprotocol#2518 · Filter by author jeffhandley opened on Apr 4, 2026