CVE-2026-25536: Lfprojects Mcp TypeScript SDK

High severity, CVSS 7.1. EPSS: 0.4% chance of exploitation in the next 30 days.

MCP TypeScript SDK is the official TypeScript SDK for Model Context Protocol servers and clients. From version 1.10.0 to 1.25.3, cross-client response data leak when a single McpServer/Server and transport instance is reused across multiple client connections, most commonly in stateless StreamableHTTPServerTransport deployments. This issue has been patched in version 1.26.0.

Affected products

• Lfprojects Mcp TypeScript SDK: from 1.10.0, before 1.26.0 (fixed in 1.26.0)

Published 2026-02-04. Last modified 2026-07-15.