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CVE-2026-111767GHSA-22jm-h49p-29qw

@modelcontextprotocol/sdk: MCP TypeScript SDK: Experimental tasks were not tied to the session that created them

modelcontextprotocol @modelcontextprotocol/sdknpmLibraries & packages
Open in ThreatlineRecord JSON
CVSS
8.6High
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.34%Chance of exploitation activity in the next 30 days, higher than 26% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in1.32.0Fixed versionGitHub
Published20 Oct 2026Updated 20 Oct 2026CVE List

What fixes it

  • 1.32.0@modelcontextprotocol/sdk, npmGitHubnpm install @modelcontextprotocol/sdk@1.32.0

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

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.

Text from GitHub Advisory Database

Affected versions 3

  • @modelcontextprotocol/sdk, npm>= 1.24.0, < 1.32.0GitHub
  • typescript-sdkaffected: >= 1.24.0, < 1.32.0CVE List
  • @modelcontextprotocol/sdk, npmfrom 1.24.0, fixed in 1.32.0OSV

References 4