{"id":"CVE-2026-72761","summary":"Webhook SSRF guard bypassed by IPv6 transition addresses (NAT64/6to4/Teredo pass is_global check) in vulnerability-lookup","details":"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.","modified":"2026-08-28T11:30:18.774355912Z","published":"2026-08-10T14:33:13.106Z","database_specific":{"cna_assigner":"CIRCL","cwe_ids":["CWE-918"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72761.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72761.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-72761"},{"type":"FIX","url":"https://github.com/vulnerability-lookup/vulnerability-lookup/commit/f3e0c6899c5b3823dcfd860fc6cb3edbedc9bf65"},{"type":"PACKAGE","url":"https://github.com/vulnerability-lookup/vulnerability-lookup"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/vulnerability-lookup/vulnerability-lookup","events":[{"introduced":"0"},{"fixed":"f3e0c6899c5b3823dcfd860fc6cb3edbedc9bf65"}],"database_specific":{"source":"REFERENCES"}}],"versions":["v5.5.0","v5.4.0","v5.3.0","v5.2.0","v5.1.0","v5.0.0","v4.6.0","v4.5.0","v4.4.0","v4.3.0","v4.2.0","v4.1.0","v4.0.0","v3.0.1","v3.0.0","v2.21.0","v2.20.0","v2.19.0","v2.18.0","v2.17.0","v2.16.1","v2.16.0","v2.15.0","v2.13.0","v2.12.0","v2.10.1","v2.10.0","v2.9.0","v2.7.1","v2.7.0","v2.6.0","v2.5.0","v2.4.0","v2.3.0","v2.2.0","v2.1.0","v1.7.0","v1.6.0","v1.5.0","v1.4.0","v1.3.0","v1.2.0","v1.1.0","v1.0.0","v0.7.0","v0.6.0","v0.5.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-72761.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"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"}]}