{"id":"CVE-2026-72761","state":"PUBLISHED","title":"Webhook SSRF guard bypassed by IPv6 transition addresses (NAT64/6to4/Teredo pass is_global check) in vulnerability-lookup","description":"The webhook URL validator in `website/notifications/webhooks.py` uses\n`ip.is_global` to reject non-public addresses after DNS resolution. IPv6\ntransition addresses (NAT64 `64:ff9b::/96`, 6to4 `2002::/16`, Teredo\n`2001:0000::/32`) are classified as globally routable by IANA, so `is_global`\nreturns `True` even when the embedded IPv4 targets a private, loopback, or\ncloud metadata destination. An attacker can register a webhook pointing at a\nhostname that resolves to a transition address to bypass the SSRF guard and\nexfiltrate vulnerability data to an internal endpoint.\n\nThe vulnerability was introduced on a non-release version. The fix was already done on HEAD. It only affects\n\norganisation running the HEAD.","publishedAt":"2026-08-10T14:33:13.106Z","updatedAt":"2026-08-10T17:00:48.661Z","severity":{"score":6.9,"label":"Medium","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N","source":"CIRCL"},"assigner":"CIRCL","products":["vulnerability-lookup vulnerability-lookup"],"affected":[{"vendor":"vulnerability-lookup","product":"vulnerability-lookup","defaultStatus":"unaffected","versions":[{"version":"0","status":"unaffected","lessThanOrEqual":"5.5.0","versionType":"semver"}],"repo":"https://github.com/vulnerability-lookup/vulnerability-lookup"}],"references":["https://github.com/vulnerability-lookup/vulnerability-lookup/commit/f3e0c6899c5b3823dcfd860fc6cb3edbedc9bf65"],"weaknesses":["CWE-918"],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/72xxx/CVE-2026-72761.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-72761","state":"PUBLISHED","datePublished":"2026-08-10T14:33:13.106Z","dateUpdated":"2026-08-10T17:00:48.661Z","assignerShortName":"CIRCL","assignerOrgId":"5a6e4751-2f3f-4070-9419-94fb35b644e8","dateReserved":"2026-08-10T14:32:19.844Z"},"containers":{"cna":{"title":"Webhook SSRF guard bypassed by IPv6 transition addresses (NAT64/6to4/Teredo pass is_global check) in vulnerability-lookup","descriptions":[{"lang":"en","value":"The webhook URL validator in `website/notifications/webhooks.py` uses\n`ip.is_global` to reject non-public addresses after DNS resolution. IPv6\ntransition addresses (NAT64 `64:ff9b::/96`, 6to4 `2002::/16`, Teredo\n`2001:0000::/32`) are classified as globally routable by IANA, so `is_global`\nreturns `True` even when the embedded IPv4 targets a private, loopback, or\ncloud metadata destination. An attacker can register a webhook pointing at a\nhostname that resolves to a transition address to bypass the SSRF guard and\nexfiltrate vulnerability data to an internal endpoint.\n\nThe vulnerability was introduced on a non-release version. The fix was already done on HEAD. It only affects\n\norganisation running the HEAD."}],"affected":[{"vendor":"vulnerability-lookup","product":"vulnerability-lookup","defaultStatus":"unaffected","versions":[{"version":"0","status":"unaffected","lessThanOrEqual":"5.5.0","versionType":"semver"}],"repo":"https://github.com/vulnerability-lookup/vulnerability-lookup"}],"references":[{"url":"https://github.com/vulnerability-lookup/vulnerability-lookup/commit/f3e0c6899c5b3823dcfd860fc6cb3edbedc9bf65","tags":["patch"]}],"metrics":[{"cvssV4_0":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"NONE","attackVector":"NETWORK","baseScore":6.9,"baseSeverity":"MEDIUM","privilegesRequired":"NONE","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"NONE","subConfidentialityImpact":"LOW","subIntegrityImpact":"NONE","userInteraction":"NONE","valueDensity":"NOT_DEFINED","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N","version":"4.0","vulnAvailabilityImpact":"NONE","vulnConfidentialityImpact":"LOW","vulnIntegrityImpact":"NONE","vulnerabilityResponseEffort":"NOT_DEFINED"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-918","description":"CWE-918 Server-Side Request Forgery (SSRF)","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"CIRCL","orgId":"5a6e4751-2f3f-4070-9419-94fb35b644e8","dateUpdated":"2026-08-10T14:33:13.106Z"},"credits":[{"lang":"en","type":"finder","value":"tonghuaroot"},{"lang":"en","type":"remediation developer","value":"Cedric Bonhomme"}],"impacts":[{"capecId":"CAPEC-664","descriptions":[{"lang":"en","value":"CAPEC-664 Server Side Request Forgery"}]}],"source":{"discovery":"UNKNOWN"},"x_generator":{"engine":"Vulnogram 0.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-10T17:00:38.181767Z","id":"CVE-2026-72761","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-10T17:00:48.661Z"}}]}}}