Affected: Apache Software Foundation Apache HTTP Server

HTTP response splitting in the core of Apache HTTP Server allows an attacker who can manipulate the Content-Type response headers of applications hosted or proxied by the server can split the HTTP response.

This vulnerability was described as CVE-2023-38709 but the patch included in Apache HTTP Server 2.4.59 did not address the issue.

Users are recommended to upgrade to version 2.4.64, which fixes this issue.

Affected: Ubuntu:22.04:LTS: apache2, Ubuntu:24.04:LTS: apache2

It was discovered that the Apache HTTP Server incorrectly handled certain Content-Type response headers. A remote attacker could possibly use this issue to perform HTTP response splitting attacks. (CVE-2024-42516)

xiaojunjie discovered that the Apache HTTP Server mod_proxy module incorrectly handled certain requests. A remote attacker could possibly use this issue to send outbound proxy requests to an arbitrary URL. (CVE-2024-43204)

John Runyon discovered that the Apache HTTP Server mod_ssl module incorrectly escaped certain data. A remote attacker could possibly use this issue to insert escape characters into log files. (CVE-2024-47252)

Sven Hebrok, Felix Cramer, Tim Storm, Maximilian Radoy, and Juraj Somorovsky discovered that the Apache HTTP Server mod_ssl module incorrectly handled TLS 1.3 session resumption. A remote attacker could possibly use this issue to bypass access control. (CVE-2025-23048)

Anthony CORSIEZ discovered that the Apache HTTP Server mod_proxy_http2 module incorrectly handled missing host headers. A remote attacker could possibly use this issue to cause the server to crash, resulting in a denial of service. (CVE-2025-49630)

Robert Merget discovered that the Apache HTTP Server mod_ssl module incorrectly handled TLS upgrades. A remote attacker could possibly use this issue to hijack an HTTP session. This update removes the old "SSLEngine optional" configuration option, possibly requiring a configuration change in certain environments. (CVE-2025-4981…