GitHub Advisoryadvisory · npm

GHSA-22jm-h49p-29qw MCP TypeScript SDK: Experimental tasks were not tied to the session that created them

HIGH Published 2026-10-20 Modified 2026-10-20 Official page ↗
Aliases
CVE-2026-111767
Ecosystem
npm
Packages
@modelcontextprotocol/sdk
Severity
High
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L
Weaknesses
CWE-639, CWE-862
Reviewed
2026-10-20

Affected packages

• npm @modelcontextprotocol/sdk: >= 1.24.0, < 1.32.0 → fixed in 1.32.0

Description

Summary In affected versions, the experimental tasks feature (`taskStore`) did not check which session created a task. Clients sharing one `InMemoryTaskStore` could list, read and cancel each other's tasks. Experimental tasks are deprecated. The 2026-07-28 specification replaced them with a redesigned extension. The best course of action is to stop using them. Am I affected? Only if your HTTP server passes `taskStore` to `McpServer` or `Server`. If `grep -ri taskstore --exclude-dir=node_modules .` finds nothing, you are not affected. Affected versions: `@modelcontextprotocol/sdk` 1.24.0 through 1.31.0. The 2.x packages are not affected. Fix Upgrade to `@modelcontextprotocol/sdk` 1.32.0 or later. Each task is now tied to the session that created it, so a client that starts a new session can no longer reach its earlier tasks. If you cannot upgrade yet, remove `taskStore`, or create one `InMemoryTaskStore` per session.

Related

Alias · CVE (1)

  • CVE-2026-111767 MCP TypeScript SDK is the official TypeScript SDK for Model Context Protocol servers and clients. vulnerability

Weakness · CWE (2)

  • CWE-639 Authorization Bypass Through User-Controlled Key weakness
  • CWE-862 Missing Authorization weakness

References