Session Management Flaw in MCP TypeScript SDK Affects Multiple Versions
CVE-2026-111767

8.6HIGH

Key Information:

Vendor

Modelcontextprotocol

Status
Typescript-sdk
Vendor
CVE Published:
20 October 2026

What is CVE-2026-111767?

The MCP TypeScript SDK, used for Model Context Protocol servers and clients, contains a session management flaw in the experimental tasks feature (taskStore). This vulnerability allows clients that share a single InMemoryTaskStore to inadvertently interact with each other's tasks, enabling them to list, read, and cancel tasks created by different sessions. The issue has been resolved in version 1.32.0, which implements necessary security measures to ensure task isolation among sessions.

Affected Version(s)

typescript-sdk >= 1.24.0, < 1.32.0

References

https://github.com/modelcontextprotocol/typescript-sdk/se...
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https://github.com/modelcontextprotocol/typescript-sdk/pu...
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https://github.com/modelcontextprotocol/typescript-sdk/co...
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CVSS V3.1

Score:
8.6
Severity:
HIGH
Confidentiality:
High
Integrity:
Low
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.