CVE-2022-24790: Debian Linux

High severity, CVSS 7.5. EPSS: 2.2% chance of exploitation in the next 30 days.

Puma is a simple, fast, multi-threaded, parallel HTTP 1.1 server for Ruby/Rack applications. When using Puma behind a proxy that does not properly validate that the incoming HTTP request matches the RFC7230 standard, Puma and the frontend proxy may disagree on where a request starts and ends. This would allow requests to be smuggled via the front-end proxy to Puma. The vulnerability has been fixed in 5.6.4 and 4.3.12. Users are advised to upgrade as soon as possible. Workaround: when deploying a proxy in front of Puma, turning on any and all functionality to make sure that the request matches the RFC7230 standard.

Affected products

• Debian Debian Linux: version 10.0 only; version 11.0 only
• Fedoraproject Fedora: version 35 only; version 36 only; version 37 only
• Puma Puma: before 4.3.12 (fixed in 4.3.12); from 5.0.0, before 5.6.4 (fixed in 5.6.4)

Published 2022-03-30. Last modified 2026-06-17.