CVE-2026-72761 Server-side request forgery in vulnerability-lookup
Attackers can bypass SSRF protections using IPv6 transition addresses to access internal endpoints and exfiltrate vulnerability data.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-72761?
CVE-2026-72761 is a medium-severity server-side request forgery vulnerability in vulnerability-lookup, published on 10 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-918
Which versions are affected by CVE-2026-72761?
How do I fix CVE-2026-72761?
No fix has been published for CVE-2026-72761 yet. Limit exposure of the affected software until one is available.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-72761 being exploited?
There is no known exploitation of CVE-2026-72761 in the wild and no public exploit code.