{"id":"CVE-2026-72761","aliases":["EUVD-2026-55637"],"status":"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.","severity":{"version":"4.0","score":6.9,"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","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00468,"percentile":0.40967,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-918"],"published":"2026-08-10T14:33:13Z","modified":"2026-10-28T02:30:31Z","products":[{"vendor":"vulnerability-lookup","product":"vulnerability-lookup"}],"references":[{"url":"https://github.com/vulnerability-lookup/vulnerability-lookup/commit/f3e0c6899c5b3823dcfd860fc6cb3edbedc9bf65","tags":["patch","fix"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72761.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-72761","tags":["advisory"]},{"url":"https://github.com/vulnerability-lookup/vulnerability-lookup","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-72761","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.","status":"published","published":"2026-08-10T14:33:13.106Z","modified":"2026-08-10T17:00:48.661Z","cvss":[{"version":"4.0","score":6.9,"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","level":"medium","assessor":"cna"}],"cwes":["CWE-918"],"updated_at":"2026-11-02T14:19:51.663093Z"}],"euvd":[{"id":"EUVD-2026-55637","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.","status":"published","published":"2026-08-10T14:33:13Z","modified":"2026-08-10T17:00:48Z","cvss":[{"version":"4.0","score":6.9,"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","level":"medium"}],"updated_at":"2026-11-02T18:02:01.941928Z"}],"nvd":[{"id":"CVE-2026-72761","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.","status":"published","published":"2026-08-10T15:17:44.783Z","modified":"2026-08-26T16:49:18.76Z","cvss":[{"version":"4.0","score":6.9,"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium","assessor":"secondary"}],"cwes":["CWE-918"],"updated_at":"2026-11-02T14:12:36.102748Z"}],"osv":[{"id":"CVE-2026-72761","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.","status":"published","published":"2026-08-10T14:33:13.106Z","modified":"2026-10-28T02:30:31.776585102Z","cvss":[{"version":"4.0","score":6.9,"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","level":"medium"}],"cwes":["CWE-918"],"updated_at":"2026-11-02T15:45:15.88521Z"}]}}