CVE-2026-25536: @modelcontextprotocol/sdk has cross-client data leak via shared server/transport instance reuse
(updated )
Cross-client data leak via two distinct issues: (1) reusing a single StreamableHTTPServerTransport across multiple client requests, and (2) reusing a single McpServer/Server instance across multiple transports. Both are most common in stateless deployments.
References
- github.com/advisories/GHSA-345p-7cg4-v4c7
- github.com/modelcontextprotocol/typescript-sdk
- github.com/modelcontextprotocol/typescript-sdk/issues/204
- github.com/modelcontextprotocol/typescript-sdk/issues/243
- github.com/modelcontextprotocol/typescript-sdk/security/advisories/GHSA-345p-7cg4-v4c7
- nvd.nist.gov/vuln/detail/CVE-2026-25536
Code Behaviors & Features
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