Vulnerability in Lfprojects Mcp Typescript Sdk
CVE-2026-25536
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.
Vulnerability class: Race Condition
EPSS: 0.003 (18.7th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N.
Affected products
- Lfprojects Mcp_typescript_sdk
- Modelcontextprotocol Typescript-sdk — versions >= 1.10.0, < 1.26.0
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Mitigation, Vendor Advisory)
- security-advisories@github.com (x_refsource_MISC, Issue Tracking, Vendor Advisory)
- security-advisories@github.com (x_refsource_MISC, Issue Tracking, Vendor Advisory)
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
Frequently asked questions
- What is CVE-2026-25536?
- CVE-2026-25536 is a high-severity vulnerability in Lfprojects Mcp Typescript Sdk, classified under Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition). CVSS score: 7.1/10. Published 2026-02-04.
- How severe is CVE-2026-25536?
- High severity. CVSS v3 base score is 7.1 out of 10.