WS-2026-0090
Published:October 02, 2026
Updated:October 07, 2026
In @modelcontextprotocol/sdk 1.24.0 through 1.31.0, the experimental tasks feature (taskStore) did not check which session created a task: InMemoryTaskStore ignored the sessionId, so clients sharing one InMemoryTaskStore on an HTTP server could list, read and cancel each other's tasks and receive their queued task messages. Fixed in 1.32.0; the 2.x packages are not affected.
Affected Packages
https://github.com/modelcontextprotocol/typescript-sdk.git (GITHUB):
Affected version(s) >=1.30.0 <1.32.0Fix Suggestion:
Update to version 1.32.0@modelcontextprotocol/sdk (NPM):
Affected version(s) >=1.24.0 <1.32.0Fix Suggestion:
Update to version 1.32.0Related Resources (3)
Do you need more information?
Contact UsCVSS v4
Base Score:
8.8
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
LOW
Vulnerable System Availability
LOW
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
8.6
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
LOW
Availability
LOW
Weakness Type (CWE)
Authorization Bypass Through User-Controlled Key