How severe is CVE-2026-25536?

CVE-2026-25536 has a CVSS 3.x base score of 7.1, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity low, and availability none.

Is CVE-2026-25536 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (18th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-25536?

CVE-2026-25536 affects Lfprojects Mcp Typescript Sdk. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-25536?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-25536 have an EU (EUVD) identifier?

Yes. CVE-2026-25536 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-5335.

When was CVE-2026-25536 published?

CVE-2026-25536 was published on 2026-02-04 and last updated on 2026-06-30.

CVE-2026-25536

CVE-2026-25536 is a high-severity vulnerability in Lfprojects Mcp Typescript Sdk with a CVSS 3.x base score of 7.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-362.

Key facts

Severity: High (CVSS 3.x base score 7.1)
EPSS exploit prediction: 0% (18th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-5335
Weakness: CWE-362
Affected product: Lfprojects Mcp Typescript Sdk
Published: 2026-02-04
Last modified: 2026-06-30

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.

Frequently asked questions

What is 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.
How severe is CVE-2026-25536?: CVE-2026-25536 has a CVSS 3.x base score of 7.1, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity low, and availability none.
Is CVE-2026-25536 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (18th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-25536?: CVE-2026-25536 affects Lfprojects Mcp Typescript Sdk. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-25536?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-25536 have an EU (EUVD) identifier?: Yes. CVE-2026-25536 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-5335.
When was CVE-2026-25536 published?: CVE-2026-25536 was published on 2026-02-04 and last updated on 2026-06-30.

References

Affected products (1)

cpe:2.3:a:lfprojects:mcp_typescript_sdk:*:*:*:*:*:*:*:*

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