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.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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
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.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.
- Record
CVE-2026-72761- CVSS 4.0
- 6.9 Medium
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-918
- Updated
- 2026-11-02
EUVDEUVD-2026-55637
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.
- Record
EUVD-2026-55637- CVSS 4.0
- 6.9 Medium
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 - Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-72761- CVSS 4.0
- 6.9 Medium
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Weakness
- CWE-918
- Updated
- 2026-11-02
OSV
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.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.
- Record
CVE-2026-72761- CVSS 4.0
- 6.9 Medium
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-918
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-72761 is a medium vulnerability (CVSS 6.9) in Vulnerability-lookup, published August 10, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.47%, the 40th percentile. No source names a fixed version.