CVE-2026-25536
CVE-2026-25536 · @modelcontextprotocol/sdk has cross-client data leak via shared server/transport instance reuse
This page contains facts from public vulnerability sources. Check the original advisory before updating.
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.
CVSS 7.1 · High · EPSS 0.3% · Fix available
- Published
- Updated
Stack: node
Affected products and versions
typescript-sdk
- Versions
- >= 1.10.0, < 1.26.0: Affected
No fix published
@modelcontextprotocol/sdk npm
- Affected ranges
- SEMVER: ≥ 1.10.0, < 1.26.0
Update to 1.26.0
Original sources
- https://github.com/modelcontextprotocol/typescript-sdk/security/advisories/GHSA-345p-7cg4-v4c7
- https://github.com/modelcontextprotocol/typescript-sdk/issues/204
- https://github.com/modelcontextprotocol/typescript-sdk/issues/243
- https://access.redhat.com/security/cve/CVE-2026-25536
- https://bugzilla.redhat.com/show_bug.cgi?id=2436937
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-25536.json
- https://access.redhat.com/errata/RHSA-2026:3960
- https://nvd.nist.gov/vuln/detail/CVE-2026-25536