---
id: "CVE-2026-111767"
kind: "vulnerability"
aliases: ["CVE-2026-111767", "GHSA-22jm-h49p-29qw"]
title: "MCP TypeScript SDK: Experimental tasks were not tied to the session that created them"
severity: "high"
cvss: 8.600000381469727
epss: 0.003449999960139394
exploited: false
status: "open"
category: "ai-tooling"
products: [{"name": "@modelcontextprotocol/sdk", "fixed": ["1.32.0"], "affected": ">= 1.24.0, < 1.32.0", "ecosystem": "npm"}]
ecosystems: ["npm"]
tags: ["ai-tooling", "cwe-639", "cwe-862", "mcp", "npm", "self-hosted", "typescript"]
not_affected_if: ["no-taskstore-usage", "sdk-2.x", "sdk-below-1.24.0"]
published_at: "2026-10-20T18:26:54+00:00"
first_seen_at: "2026-10-23T19:11:32+00:00"
updated_at: "2026-10-23T20:56:18+00:00"
sources: [{"source": "ghsa", "url": "https://github.com/advisories/GHSA-22jm-h49p-29qw", "first_seen_at": "2026-10-23T19:11:32+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-111767", "first_seen_at": "2026-10-23T21:57:21+00:00"}]
---

# MCP TypeScript SDK: Experimental tasks were not tied to the session that created them

The MCP TypeScript SDK's experimental tasks feature did not check which session created a task, so clients sharing one InMemoryTaskStore could list, read and cancel each other's tasks. The flaw is in the MCP server code path, so it is ai-tooling.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- npm:@modelcontextprotocol/sdk affected >= 1.24.0, < 1.32.0 fixed 1.32.0

## How to check

grep -ri taskstore --exclude-dir=node_modules . (no hits means not affected)
Check package.json or lockfile for @modelcontextprotocol/sdk between 1.24.0 and 1.31.0
Confirm whether McpServer or Server is constructed with a taskStore option

## Fix

Upgrade @modelcontextprotocol/sdk to 1.32.0 or later.
If you cannot upgrade, remove taskStore or create one InMemoryTaskStore per session; the upstream advisory recommends stopping use of experimental tasks.

## Timeline

- 2026-10-23T19:11:32+00:00 ghsa https://github.com/advisories/GHSA-22jm-h49p-29qw
- 2026-10-23T21:57:21+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-111767

## From the sources

### 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.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_