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
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.004 (27.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 27th percentile — 27.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001
Affected products
- Lfprojects Mcp Typescript Sdk
- Modelcontextprotocol Typescript-Sdk — versions >= 1.10.0, < 1.26.0
Weakness classification (CWE)
References
- github.com/modelcontextprotocol/typescript-sdk/security/advisories/GHSA-345p-7c… (Mitigation, Vendor Advisory)
- github.com/modelcontextprotocol/typescript-sdk/issues/204 (Issue Tracking, Vendor Advisory)
- github.com/modelcontextprotocol/typescript-sdk/issues/243 (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.