{"id":"EUVD-2026-30488","enisaUuid":"f8d15dd5-9f10-3445-8053-da50b3f7e80f","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\u0027s 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\u0027s 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.","datePublished":"May 14, 2026, 9:02:40 PM","dateUpdated":"May 15, 2026, 6:05:09 PM","baseScore":6.3,"baseScoreVersion":"4.0","baseScoreVector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:N/SA:N","references":"https://github.com/modelcontextprotocol/registry/security/advisories/GHSA-r48c-v28r-pf6v\n","aliases":"CVE-2026-44430\nGHSA-r48c-v28r-pf6v\n","assigner":"GitHub_M","epss":0.29,"enisaIdProduct":[{"id":"a847dd2e-09df-3f25-acc3-bec3ace2bebd","product":{"name":"registry","vendor":{"name":"modelcontextprotocol"}},"product_version":"\u003c 1.7.7"}],"enisaIdVendor":[{"id":"6d5a541e-cc8f-38f9-a887-8c68b0f6351f","vendor":{"name":"modelcontextprotocol"}}],"enisaIdVulnerability":[{"id":"126bfc2e-9151-3c58-997d-22a207e8fd7a","vulnerability":{"id":"CVE-2026-44430","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\u0027s 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\u0027s 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.","datePublished":"May 14, 2026, 9:02:40 PM","dateUpdated":"May 15, 2026, 6:05:09 PM","status":"PUBLISHED","baseScore":6.3,"baseScoreVersion":"4.0","baseScoreVector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:N/SA:N","references":"https://github.com/modelcontextprotocol/registry/security/advisories/GHSA-r48c-v28r-pf6v\n","enisa_id":"EUVD-2026-30488\n","assigner":"GitHub_M","epss":0.29,"dataProcessed":"Oct 28, 2026, 7:17:27 AM","vulnerabilityProduct":[{"id":"199bcfca-43d5-3e57-8848-88cac3b7b33a","product":{"name":"registry","vendor":{"name":"modelcontextprotocol"}},"product_version":"\u003c 1.7.7"}],"vulnerabilityVendor":[{"id":"aae6d096-e52f-3622-a888-f3fecd325d4c","vendor":{"name":"modelcontextprotocol"}}]}},{"id":"db9f6363-a396-3b25-ba85-4895dee91eda","vulnerability":{"id":"GHSA-r48c-v28r-pf6v","description":"MCP Registry has an unauthenticated SSRF: HTTP namespace verification dials 6to4 / NAT64 / site-local IPv6 addresses, bypassing private-address allowlist","datePublished":"May 8, 2026, 5:20:56 PM","dateUpdated":"May 15, 2026, 11:46:20 PM","baseScore":0.0,"references":"https://github.com/modelcontextprotocol/registry/security/advisories/GHSA-r48c-v28r-pf6v\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-44430\nhttps://github.com/modelcontextprotocol/registry/pull/1250\nhttps://github.com/modelcontextprotocol/registry/commit/f5f40bd98084466eaf18fe48ea62a0d534caa774\nhttps://github.com/modelcontextprotocol/registry\nhttps://github.com/modelcontextprotocol/registry/releases/tag/v1.7.7\n","enisa_id":"EUVD-2026-30488\n","aliases":"GHSA-r48c-v28r-pf6v\nCVE-2026-44430\n","epss":0.0,"dataProcessed":"Oct 25, 2026, 1:55:50 AM","vulnerabilityProduct":[],"vulnerabilityVendor":[]}}],"enisaIdAdvisory":[]}