CVE-2026-25536

Name: CVE-2026-25536
Creator: NVD / NIST
Published: 2026-02-04T22:15:59.663+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.1/10EPSS 0.24%

Last modified Jun 17, 2026

CVE-2026-25536 is a high-severity vulnerability rated 7.1/10 on the CVSS scale. 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. EPSS estimates a 0.24% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

7.1/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N

EPSS Probability

0.24%

14.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-362

Affected Software

Vendor	Product	Versions
Lfprojects	Mcp Typescript Sdk	>= 1.10.0, < 1.26.0

References

https://github.com/modelcontextprotocol/typescript-sdk/issues/204Issue Tracking, Vendor Advisory
https://github.com/modelcontextprotocol/typescript-sdk/issues/243Issue Tracking, Vendor Advisory
https://github.com/modelcontextprotocol/typescript-sdk/security/advisories/GHSA-345p-7cg4-v4c7Mitigation, Vendor Advisory

Timeline

Published: Feb 4, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-25536?

How severe is CVE-2026-25536?

CVE-2026-25536 has a CVSS score of 7.1/10 (HIGH severity). The EPSS model estimates a 0.24% probability of exploitation in the next 30 days.

How do I fix CVE-2026-25536?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-25536?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST