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.
Advisories
Source ID Title
Github GHSA Github GHSA GHSA-345p-7cg4-v4c7 @modelcontextprotocol/sdk has cross-client data leak via shared server/transport instance reuse
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Thu, 05 Feb 2026 21:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 05 Feb 2026 12:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-367
References
Metrics threat_severity

None

threat_severity

Important


Thu, 05 Feb 2026 11:45:00 +0000

Type Values Removed Values Added
First Time appeared Modelcontextprotocol
Modelcontextprotocol typescript-sdk
Vendors & Products Modelcontextprotocol
Modelcontextprotocol typescript-sdk

Wed, 04 Feb 2026 21:45:00 +0000

Type Values Removed Values Added
Description 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.
Title @modelcontextprotocol/sdk has cross-client data leak via shared server/transport instance reuse
Weaknesses CWE-362
References
Metrics cvssV3_1

{'score': 7.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-02-05T20:58:17.103Z

Reserved: 2026-02-02T19:59:47.374Z

Link: CVE-2026-25536

cve-icon Vulnrichment

Updated: 2026-02-05T20:58:11.079Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-02-04T22:15:59.663

Modified: 2026-02-05T14:57:20.563

Link: CVE-2026-25536

cve-icon Redhat

Severity : Important

Publid Date: 2026-02-04T21:29:38Z

Links: CVE-2026-25536 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-02-05T11:39:39Z

Weaknesses