{"id":"CVE-2026-79749","summary":"MCPHub: SSRF Guard Bypass via IPv6 Transition Addresses in URL Validation","details":"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.","aliases":["GHSA-pr4x-3pc7-2fhw"],"modified":"2026-09-02T03:47:22.772689393Z","published":"2026-08-31T17:54:45.423Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/79xxx/CVE-2026-79749.json","cna_assigner":"GitHub_M","cwe_ids":["CWE-918"]},"references":[{"type":"WEB","url":"https://github.com/samanhappy/mcphub/releases/tag/v1.0.32"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/79xxx/CVE-2026-79749.json"},{"type":"ADVISORY","url":"https://github.com/samanhappy/mcphub/security/advisories/GHSA-pr4x-3pc7-2fhw"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-79749"},{"type":"FIX","url":"https://github.com/samanhappy/mcphub/commit/2b10ae36112ce68deebf910b22505d44efcef552"},{"type":"FIX","url":"https://github.com/samanhappy/mcphub/pull/1069"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/samanhappy/mcphub","events":[{"introduced":"0"},{"fixed":"2b10ae36112ce68deebf910b22505d44efcef552"},{"fixed":"20e3ba73aea03c493669f90526436a9a576f9c6c"}],"database_specific":{"source":["AFFECTED_FIELD","REFERENCES"],"extracted_events":[{"introduced":"0"},{"fixed":"1.0.32"}]}}],"versions":["v1.0.31","v1.0.30","v1.0.29","v1.0.28","v1.0.27","v1.0.26","v1.0.25","v1.0.24","v1.0.23","v1.0.22","v1.0.21","v1.0.20","v1.0.19","v1.0.18","v1.0.17","v1.0.16","v1.0.15","v1.0.14","v1.0.13","v1.0.12","v1.0.11","v1.0.10","v1.0.9","v1.0.8","v1.0.7","v1.0.6","v1.0.5","v1.0.4","v1.0.3","v1.0.2","v1.0.1","v1.0.0","v0.12.17","v0.12.16","v0.12.15","v0.12.14","v0.12.13","v0.12.12","v0.12.11","v0.12.10","v0.12.9","v0.12.8","v0.12.7","v0.12.6","v0.12.5","v0.12.4","v0.12.3","v0.12.2","v0.12.1","v0.12.0","v0.11.13","v0.11.12","v0.11.11","v0.11.10","v0.11.9","v0.11.8","v0.11.7","v0.11.6","v0.11.5","v0.11.4","v0.11.3","v0.11.2","v0.11.1","v0.11.0","v0.10.6","v0.10.5","v0.10.4","v0.10.3","v0.10.2","v0.10.1","v0.10.0","v0.9.16","v0.9.15","v0.9.14","v0.9.13","v0.9.12","v0.9.11","v0.9.10","v0.9.9","v0.9.8","v0.9.7","v0.9.6","v0.9.5","v0.9.4","v0.9.3","v0.9.2","v0.9.1","v0.9.0","v0.8.7","v0.8.6","v0.8.5","v0.8.4","v0.8.3","v0.8.2","v0.8.1","v0.8.0","v0.7.7","v0.7.6","v0.7.5","v0.7.4","v0.7.3","v0.7.2","v0.7.1","v0.7.0","v0.6.2","v0.6.1","v0.6.0","v0.5.4","v0.5.3","v0.5.2","v0.5.1","v0.5.0","v0.4.3","v0.4.2","v0.4.1","v0.4.0","v0.3.8","v0.3.7","v0.3.6","v0.3.5","v0.3.4","v0.3.3","v0.3.2","v0.3.1","v0.3.0","v0.2.0","v0.1.1","v0.1.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-79749.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"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"}]}