CVE-2026-72761 Webhook SSRF guard bypassed by IPv6 transition addresses (NAT64/6to4/Teredo pass is_global check) in vulnerability-lookup

The webhook URL validator in website/notifications/webhooks.py uses ip.isglobal to reject non-public addresses after DNS resolution. IPv6 transition addresses NAT64 64:ff9b::/96, 6to4 2002::/16, Teredo 2001:0000::/32 are classified as globally routable by IANA, so isglobal returns True even when...