CVE-2026-72761 (GCVE-0-2026-72761)

Vulnerability from cvelistv5 – Published: 2026-08-10 14:33 – Updated: 2026-08-10 17:00
VLAI
Title
Webhook SSRF guard bypassed by IPv6 transition addresses (NAT64/6to4/Teredo pass is_global check) in vulnerability-lookup
Summary
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.
Severity
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
SSVC
Exploitation: none Automatable: yes Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
  • CWE-918 - Server-Side Request Forgery (SSRF)
Assigner
References
Impacted products
Vendor Product Version
vulnerability-lookup vulnerability-lookup Unaffected: 0 , ≤ 5.5.0 (semver)
Create a notification for this product.
Credits
tonghuaroot Cedric Bonhomme
Show details on NVD website
To clipboard 

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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