HIGHCVE-2026-25536Published Modified CNA GitHub_M
CVE-2026-25536: @modelcontextprotocol/sdk has cross-client data leak via shared server/transport instance reuse
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.
Metrics
- CVSS v3.1
- 7.1
- Severity
- HIGH
- Fixed in
- —
- Affected Products
- 1
Affected packages
- modelcontextprotocol / typescript-sdk>= 1.10.0, < 1.26.0
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N