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.
`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.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| vulnerability-lookup | vulnerability-lookup | unaffected |
|
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Solution
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References
History
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
|
Projects
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MITRE
Status: PUBLISHED
Assigner: CIRCL
Published:
Updated: 2026-08-10T14:33:13.106Z
Reserved: 2026-08-10T14:32:19.844Z
Link: CVE-2026-72761
Vulnrichment
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NVD
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Redhat
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OpenCVE Enrichment
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Weaknesses