2026-02-04 · 2026-Q1
MCP TypeScript SDK Cross-Client Data Leak
Primary layerL6 Identity / Run
Which agent, run, or tenant is this?
- Fixable
- Vendor patch
- Vendor response
- Patched
- In the wild
- No
- Actor
- Attacker
Target
MCP TypeScript SDK (v1.10.0-1.25.3)
Impact
Tool results, resource content, and error messages routed to wrong client in multi-tenant deployments
Root cause
Race condition in response multiplexing of StreamableHTTPServerTransport
CVE
Sources
Catalog
Cite this: AgentProv incident record: MCP TypeScript SDK Cross-Client Data Leak (2026-02-04). https://agentprov.com/incidents/2026-02-04-mcp-typescript-sdk-cross-client-data-leak
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