CVE-2026-111767: MCP TypeScript SDK experimental tasks lacked session isolation

# CVE-2026-111767: MCP TypeScript SDK experimental tasks lacked session isolation

https://gcdradar.vercel.app/incidents/cve-2026-111767-mcp-typescript-sdk-experimental-tasks-lacked · AIR-2026-1431 · closed 2026-10-20

- Lane: Patch now
- Severity: 2 (Disclosed vulnerability)
- Fix status: Fix status unknown
- First reported: 2026-10-20
- AI role: Attack on AI
- Products: MCP TypeScript SDK
- CVE ids: CVE-2026-111767
- CVSS: 8.6

## Summary

An access control vulnerability in the MCP TypeScript SDK allowed clients sharing an in-memory task store to view and cancel each other's tasks due to missing session validation. The maintainers recommended stopping the use of the deprecated experimental tasks feature.

## What to do

No action recorded; read the sources below and the vendor's advisory.

## Latest updates

- 2026-10-20: CVE-2026-111767: MCP TypeScript SDK is the official TypeScript SDK for Model Context Protocol servers and clients. (https://nvd.nist.gov/vuln/detail/CVE-2026-111767)
- 2026-10-20: CVE-2026-111767: MCP TypeScript SDK: Experimental tasks were not tied to the session that created them (https://github.com/advisories/GHSA-22jm-h49p-29qw)

## Sources

- 2026-10-20 GitHub Advisory Database: CVE-2026-111767: MCP TypeScript SDK: Experimental tasks were not tied to the session that created them https://github.com/advisories/GHSA-22jm-h49p-29qw
- 2026-10-20 NVD: CVE-2026-111767: MCP TypeScript SDK is the official TypeScript SDK for Model Context Protocol servers and clients. https://nvd.nist.gov/vuln/detail/CVE-2026-111767

Verify against the vendor's advisory before changing production. Data CC BY-SA 4.0, https://gcdradar.vercel.app.