CVE-2026-44430
4.0 · MEDIUMOverview
CVE-2026-44430 is a medium-severity vulnerability affecting lfprojects mcp_registry. It was published on May 14, 2026 and has a CVSS 3.1 base score of 4.0 (MEDIUM).
This vulnerability has a CVSS 3.1 base score of 4.0, rated MEDIUM. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical Description
The MCP Registry provides MCP clients with a list of MCP servers, like an app store for MCP servers. Prior to 1.7.7, the Registry's HTTP-based namespace verification (POST /v0/auth/http, POST /v0.1/auth/http) uses safeDialContext (internal/api/handlers/v0/auth/http.go:67-110) to refuse dialling private/internal addresses when fetching the well-known public-key file from a publisher-supplied domain. The blocklist (isBlockedIP, lines 125-133) relies entirely on Go stdlib's IsLoopback / IsPrivate / IsLinkLocalUnicast / IsMulticast / IsUnspecified plus a manual CGNAT range. None of these cover IPv6 6to4 (2002::/16), NAT64 (64:ff9b::/96 and 64:ff9b:1::/48 per RFC 8215), or deprecated site-local (fec0::/10) — all of which encode arbitrary IPv4 in the address bits and tunnel to RFC1918 / cloud-metadata services on dual-stack / NAT64-enabled hosts. This vulnerability is fixed in 1.7.7.
Remediation
Check the references section for vendor advisories and patches from lfprojects. Update mcp_registry 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_registry | >= 0, < 1.7.7 | Affected |
Frequently Asked Questions
What is CVE-2026-44430?
CVE-2026-44430 is a medium-severity vulnerability affecting lfprojects mcp_registry. It was published on May 14, 2026 and has a CVSS 3.1 base score of 4.0 (MEDIUM).
How severe is CVE-2026-44430?
This vulnerability has a CVSS 3.1 base score of 4.0, rated MEDIUM. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2026-44430?
Check the references section for vendor advisories and patches from lfprojects. Update mcp_registry 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-2026-44430?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-44430 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
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