CVE-2026-42596: Thecodingmachine Gotenberg

Critical severity, CVSS 9.4. EPSS: 1.8% chance of exploitation in the next 30 days.

Gotenberg is a Docker-powered stateless API for PDF files. Prior to 8.31.0, the default deny-lists used by Gotenberg's downloadFrom feature and webhook feature are bypassable. Because the filter is regex-based and case-sensitive, an unauthenticated attacker can supply URLs such as http://[::ffff:127.0.0.1]:... and reach loopback or private HTTP services that the default deny-list is intended to block. This crosses a real security boundary because an external caller can force the server to make outbound requests to internal-only targets. This vulnerability is fixed in 8.31.0.

Affected products

• Thecodingmachine Gotenberg: before 8.31.0 (fixed in 8.31.0)

Published 2026-05-14. Last modified 2026-06-17.