How serious is CVE-2025-66414?

This vulnerability has a CVSS score of 7.6 out of 10, classified as HIGH severity. Proof-of-concept exploit code is publicly available, making this an active threat.

Is there exploit code available for CVE-2025-66414?

Yes, proof-of-concept exploit code for CVE-2025-66414 is publicly available on GitHub and security research platforms. This increases the risk of active exploitation.

Which products are affected by CVE-2025-66414?

CVE-2025-66414 affects lfprojects mcp typescript sdk. Check the full CVE details for specific version information.

How do I fix CVE-2025-66414?

To remediate CVE-2025-66414, check for security patches from lfprojects. Apply all available updates and security patches. If no patch is available, implement recommended workarounds or security controls to mitigate the risk.

CVE-2025-66414

High

|7.6

Exploit Available

Plain English Summary

AI-powered analysis for quick understanding

An attacker can exploit this vulnerability to send unauthorized requests to a local MCP server running on a user's machine, potentially accessing sensitive resources or tools. This can happen if the server is running without authentication on localhost and does not have DNS rebinding protection enabled, which is a risky setup that should be avoided.

Technical Description

MCP TypeScript SDK is the official TypeScript SDK for Model Context Protocol servers and clients. Prior to 1.24.0, The Model Context Protocol (MCP) TypeScript SDK does not enable DNS rebinding protection by default for HTTP-based servers. When an HTTP-based MCP server is run on localhost without authentication with StreamableHTTPServerTransport or SSEServerTransport and has not enabled enableDnsRebindingProtection, a malicious website could exploit DNS rebinding to bypass same-origin policy restrictions and send requests to the local MCP server. This could allow an attacker to invoke tools or access resources exposed by the MCP server on behalf of the user in those limited circumstances. Note that running HTTP-based MCP servers locally without authentication is not recommended per MCP security best practices. This issue does not affect servers using stdio transport. This vulnerability is fixed in 1.24.0.

CVSS Vector Analysis

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionRequired

Confidentiality ImpactHigh

Integrity ImpactHigh

Availability ImpactHigh

ScopeChanged

Vector String

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Exploit Resources

Search for proof-of-concept code and exploit modules

GitHub Search Exploit-DB Nuclei Templates Metasploit Vulners

Official References

NIST NVD

Est. Bounty

$2,263($1K-$5K)

Vendor Response

Grade FPatched in 98 days

Quick Information

Published

Dec 2, 2025

4 months ago

Last Modified

Mar 10, 2026

28 days ago

Vendor

lfprojects

Product

mcp typescript sdk

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