Gotenberg 8.31.0 before 8.38.0 contains a server-side request forgery vulnerability in IsPublicIP() that allows unauthenticated attackers to bypass private-IP deny-list protections using IPv6 zone identifiers. Attackers can append a zone such as %25eth0 to the unspecified address or blocked IPv6 prefixes in downloadFrom, webhook, or Chromium/LibreOffice URLs to reach internal services and read responses in the returned PDF.
CWE-918