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.
Published: 2026-08-10
Score: 6.9 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Analysis and contextual insights are available on OpenCVE Cloud.

Remediation

No vendor fix or workaround currently provided.

Additional remediation guidance may be available on OpenCVE Cloud.

Tracking

Sign in to view the affected projects.

Advisories

No advisories yet.

History

Tue, 11 Aug 2026 15:45:00 +0000

Type Values Removed Values Added
First Time appeared Circl
Circl vulnerability-lookup
Vendors & Products Circl
Circl vulnerability-lookup

Mon, 10 Aug 2026 18:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Mon, 10 Aug 2026 14:45:00 +0000

Type Values Removed Values Added
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.
Title Webhook SSRF guard bypassed by IPv6 transition addresses (NAT64/6to4/Teredo pass is_global check) in vulnerability-lookup
Weaknesses CWE-918
References
Metrics cvssV4_0

{'score': 6.9, 'vector': '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'}


Subscriptions

Circl Vulnerability-lookup
cve-icon MITRE

Status: PUBLISHED

Assigner: CIRCL

Published:

Updated: 2026-08-10T17:00:48.661Z

Reserved: 2026-08-10T14:32:19.844Z

Link: CVE-2026-72761

cve-icon Vulnrichment

Updated: 2026-08-10T17:00:45.442Z

cve-icon NVD

Status : Received

Published: 2026-08-10T15:17:44.783

Modified: 2026-08-10T17:17:38.293

Link: CVE-2026-72761

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-11T14:22:38Z

Weaknesses