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Medium 6.9Published Aug 10, 2026

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

Updated under an hour ago ()

Does this affect you?

It affects vulnerability-lookup. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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.

CVSS
6.9 MEDIUM (v4.0, CNA)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
Weakness (CWE)
CWE-918
Known exploited
Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days)
Not loaded for this CVE
Assigned by
CIRCL
NVD analysis
Deferred
Record last updated
Aug 10, 2026
First seen by InfoSec Signals
Oct 9, 2026

Affected products

Affected products
vulnerability-lookup vulnerability-lookup
vulnerability_lookup:vulnerability_lookup (from the name)
through 5.5.0 not affected
CNA record

References

  • patch

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.

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