{"id":"CVE-2026-79749","state":"PUBLISHED","title":"MCPHub: SSRF Guard Bypass via IPv6 Transition Addresses in URL Validation","description":"MCPHub is a unified hub for centrally managing and dynamically orchestrating multiple MCP servers/APIs into separate endpoints with flexible routing strategies. Prior to version 1.0.32, MCPHub's SSRF guard in src/utils/ssrf.ts uses a custom isBlockedIpv6 function that only checks for loopback, link-local, unique-local, IPv4-mapped, and IPv4-compatible IPv6 addresses. IPv6 transition address families -- NAT64 (64:ff9b::/96), 6to4 (2002::/16), and Teredo (2001::/32) -- are not checked. An attacker who can specify a URL for an MCP server connection can encode a private IPv4 address inside one of these IPv6 forms to bypass the SSRF guard and reach internal infrastructure. This issue has been patched in version 1.0.32.","publishedAt":"2026-08-31T17:54:45.423Z","updatedAt":"2026-08-31T18:48:57.445Z","severity":{"score":7.6,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["samanhappy mcphub"],"affected":[{"vendor":"samanhappy","product":"mcphub","versions":[{"version":"< 1.0.32","status":"affected"}]}],"references":["https://github.com/samanhappy/mcphub/security/advisories/GHSA-pr4x-3pc7-2fhw","https://github.com/samanhappy/mcphub/pull/1069","https://github.com/samanhappy/mcphub/commit/2b10ae36112ce68deebf910b22505d44efcef552","https://github.com/samanhappy/mcphub/releases/tag/v1.0.32"],"weaknesses":["CWE-918"],"ingestedAt":"2026-10-29T20:13:07.220Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/79xxx/CVE-2026-79749.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-79749","state":"PUBLISHED","datePublished":"2026-08-31T17:54:45.423Z","dateUpdated":"2026-08-31T18:48:57.445Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-08-25T14:08:18.109Z"},"containers":{"cna":{"title":"MCPHub: SSRF Guard Bypass via IPv6 Transition Addresses in URL Validation","descriptions":[{"lang":"en","value":"MCPHub is a unified hub for centrally managing and dynamically orchestrating multiple MCP servers/APIs into separate endpoints with flexible routing strategies. Prior to version 1.0.32, MCPHub's SSRF guard in src/utils/ssrf.ts uses a custom isBlockedIpv6 function that only checks for loopback, link-local, unique-local, IPv4-mapped, and IPv4-compatible IPv6 addresses. IPv6 transition address families -- NAT64 (64:ff9b::/96), 6to4 (2002::/16), and Teredo (2001::/32) -- are not checked. An attacker who can specify a URL for an MCP server connection can encode a private IPv4 address inside one of these IPv6 forms to bypass the SSRF guard and reach internal infrastructure. This issue has been patched in version 1.0.32."}],"affected":[{"vendor":"samanhappy","product":"mcphub","versions":[{"version":"< 1.0.32","status":"affected"}]}],"references":[{"url":"https://github.com/samanhappy/mcphub/security/advisories/GHSA-pr4x-3pc7-2fhw","name":"https://github.com/samanhappy/mcphub/security/advisories/GHSA-pr4x-3pc7-2fhw","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/samanhappy/mcphub/pull/1069","name":"https://github.com/samanhappy/mcphub/pull/1069","tags":["x_refsource_MISC"]},{"url":"https://github.com/samanhappy/mcphub/commit/2b10ae36112ce68deebf910b22505d44efcef552","name":"https://github.com/samanhappy/mcphub/commit/2b10ae36112ce68deebf910b22505d44efcef552","tags":["x_refsource_MISC"]},{"url":"https://github.com/samanhappy/mcphub/releases/tag/v1.0.32","name":"https://github.com/samanhappy/mcphub/releases/tag/v1.0.32","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"LOW","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":7.6,"baseSeverity":"HIGH","vectorString":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-918","lang":"en","description":"CWE-918: Server-Side Request Forgery (SSRF)","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-08-31T17:54:45.423Z"},"source":{"advisory":"GHSA-pr4x-3pc7-2fhw","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/samanhappy/mcphub/security/advisories/GHSA-pr4x-3pc7-2fhw","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-31T18:48:33.754446Z","id":"CVE-2026-79749","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-31T18:48:57.445Z"}}]}}}