CVE-2023-22795: Debian Linux

High severity, CVSS 7.5. EPSS: 2.3% chance of exploitation in the next 30 days.

A regular expression based DoS vulnerability in Action Dispatch <6.1.7.1 and <7.0.4.1 related to the If-None-Match header. A specially crafted HTTP If-None-Match header can cause the regular expression engine to enter a state of catastrophic backtracking, when on a version of Ruby below 3.2.0. This can cause the process to use large amounts of CPU and memory, leading to a possible DoS vulnerability All users running an affected release should either upgrade or use one of the workarounds immediately.

Affected products

• Debian Debian Linux: version 11.0 only
• Rubyonrails Rails: before 6.1.7.1 (fixed in 6.1.7.1); from 7.0.0, before 7.0.4.1 (fixed in 7.0.4.1)

Published 2023-02-09. Last modified 2026-06-17.