CVE-2026-34742
8.1 · HIGHOverview
CVE-2026-34742 is a high-severity vulnerability affecting lfprojects mcp_go_sdk. It was published on April 2, 2026 and has a CVSS 3.1 base score of 8.1 (HIGH).
This vulnerability has a CVSS 3.1 base score of 8.1, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical Description
The Go MCP SDK used Go's standard encoding/json. Prior to version 1.4.0, the Model Context Protocol (MCP) Go 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 StreamableHTTPHandler or SSEHandler, 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. This issue has been patched in version 1.4.0.
Remediation
Check the references section for vendor advisories and patches from lfprojects. Update mcp_go_sdk to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| lfprojects | mcp_go_sdk | >= 0, < 1.4.0 | Affected |
References
Frequently Asked Questions
What is CVE-2026-34742?
CVE-2026-34742 is a high-severity vulnerability affecting lfprojects mcp_go_sdk. It was published on April 2, 2026 and has a CVSS 3.1 base score of 8.1 (HIGH).
How severe is CVE-2026-34742?
This vulnerability has a CVSS 3.1 base score of 8.1, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2026-34742?
Check the references section for vendor advisories and patches from lfprojects. Update mcp_go_sdk to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-34742?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-34742 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
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