Vulnerability Description
The webhook URL validator in `website/notifications/webhooks.py` uses `ip.is_global` 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 `is_global` returns `True` even when the embedded IPv4 targets a private, loopback, or cloud metadata destination. An attacker can register a webhook pointing at a hostname that resolves to a transition address to bypass the SSRF guard and exfiltrate vulnerability data to an internal endpoint. The vulnerability was introduced on a non-release version. The fix was already done on HEAD. It only affects organisation running the HEAD.
Related Weaknesses (CWE)
References
FAQ
What is CVE-2026-72761?
CVE-2026-72761 is a documented vulnerability. The webhook URL validator in `website/notifications/webhooks.py` uses `ip.is_global` to reject non-public addresses after DNS resolution. IPv6 transition addresses (NAT64 `64:ff9b::/96`, 6to4 `2002::/...
How severe is CVE-2026-72761?
CVSS scoring is not yet available for CVE-2026-72761. Check NVD for updates.
Is there a patch for CVE-2026-72761?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.