CVE-2022-39957: Debian Linux

High severity, CVSS 7.5. EPSS: 1% chance of exploitation in the next 30 days.

The OWASP ModSecurity Core Rule Set (CRS) is affected by a response body bypass. A client can issue an HTTP Accept header field containing an optional "charset" parameter in order to receive the response in an encoded form. Depending on the "charset", this response can not be decoded by the web application firewall. A restricted resource, access to which would ordinarily be detected, may therefore bypass detection. The legacy CRS versions 3.0.x and 3.1.x are affected, as well as the currently supported versions 3.2.1 and 3.3.2. Integrators and users are advised to upgrade to 3.2.2 and 3.3.3 respectively.

Affected products

• Debian Debian Linux: version 10.0 only
• Fedoraproject Fedora: version 35 only; version 36 only; version 37 only
• Owasp Owasp Modsecurity Core Rule Set: from 3.0.0, before 3.2.2 (fixed in 3.2.2); from 3.3.0, before 3.3.3 (fixed in 3.3.3)

Published 2022-09-20. Last modified 2026-06-17.