In some mod_ssl configurations on Apache HTTP Server versions through to 2.4.63, an HTTP desynchronisation attack allows a man-in-the-middle attacker to hijack an HTTP session via a TLS upgrade.
Only configurations using "SSLEngine optional" to enable TLS upgrades are affected. Users are recommended to upgrade to version 2.4.64, which removes support for TLS upgrade.
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Alma_linux | — | Upgrade httpd-coreUpgrade mod_http2Upgrade mod_ldapUpgrade httpd-filesystemUpgrade httpd-manualUpgrade mod_sslUpgrade mod_sessionUpgrade httpd-develUpgrade mod_mdUpgrade mod_luaUpgrade mod_proxy_htmlUpgrade httpd-toolsUpgrade httpd | Sep 5, 2025 | Sep 3, 2025 |
| Alpine Linux | — | Upgrade apache2 | Aug 8, 2025 | Jul 10, 2025 |
| Amazon Linux Ami 2 | — | Upgrade httpd-manualUpgrade httpd-toolsUpgrade mod_proxy_htmlUpgrade httpdUpgrade httpd-debuginfoUpgrade mod_mdUpgrade mod_sslUpgrade httpd-develUpgrade mod_sessionUpgrade httpd-filesystemUpgrade mod_ldap | May 20, 2026 | May 20, 2026 |
| Amazon_linux_2023 | — | Upgrade httpd-toolsUpgrade httpdUpgrade httpd-manualUpgrade httpd-develUpgrade httpd-coreUpgrade httpd-core-debuginfoUpgrade mod_lua-debuginfoUpgrade httpd-debugsourceUpgrade httpd-tools-debuginfoUpgrade mod_session-debuginfoUpgrade mod_proxy_html-debuginfoUpgrade mod_sessionUpgrade mod_luaUpgrade httpd-filesystemUpgrade httpd-debuginfoUpgrade mod_ldapUpgrade mod_ssl-debuginfoUpgrade mod_sslUpgrade mod_proxy_htmlUpgrade mod_ldap-debuginfo | Aug 5, 2025 | Jul 14, 2025 |
| Apache Httpd | — | Upgrade to the latest version of Apache HTTPD | Jul 18, 2025 | Jul 10, 2025 |
| Debian | — | Upgrade apache2 | Jul 14, 2025 | Jul 10, 2025 |
| Freebsd | — | Upgrade apache24 | Jul 13, 2025 | Jul 11, 2025 |
| Gentoo Linux | — | Upgrade www-servers/apache. | Aug 16, 2026 | Aug 13, 2026 |
| Huawei Euleros 2_0_sp10 | — | Upgrade mod_sslUpgrade httpd-filesystemUpgrade httpdUpgrade httpd-tools | Nov 12, 2025 | Sep 9, 2025 |
| Huawei Euleros 2_0_sp11 | — | Upgrade mod_sslUpgrade httpdUpgrade httpd-toolsUpgrade httpd-filesystem | Oct 14, 2025 | Sep 9, 2025 |
| Huawei Euleros 2_0_sp12 | — | Upgrade httpd-filesystemUpgrade httpdUpgrade mod_sslUpgrade httpd-tools | Sep 15, 2025 | Sep 9, 2025 |
| Huawei Euleros 2_0_sp13 | — | Upgrade httpd-filesystemUpgrade httpdUpgrade mod_sslUpgrade httpd-tools | Oct 24, 2025 | Sep 9, 2025 |
| Oracle_linux | — | Upgrade httpdUpgrade mod_sessionUpgrade mod_mdUpgrade httpd-manualUpgrade httpd-develUpgrade mod_sslUpgrade mod_ldapUpgrade mod_http2Upgrade httpd-filesystemUpgrade mod_luaUpgrade mod_proxy_htmlUpgrade httpd-coreUpgrade httpd-tools | Sep 3, 2025 | Jul 14, 2025 |
| Redhat_linux | — | Upgrade mod_proxy_htmlUpgrade mod_mdUpgrade mod_md-debugsourceUpgrade mod_ldap-debuginfoUpgrade httpd-toolsUpgrade mod_http2-debuginfoUpgrade httpd-core-debuginfoUpgrade mod_ssl-debuginfoUpgrade mod_luaUpgrade httpdUpgrade httpd-develUpgrade httpd-tools-debuginfoUpgrade mod_session-debuginfoUpgrade httpd-debugsourceUpgrade mod_sessionUpgrade mod_proxy_html-debuginfoUpgrade mod_lua-debuginfoUpgrade mod_http2Upgrade mod_md-debuginfoUpgrade httpd-filesystemUpgrade httpd-debuginfoUpgrade mod_http2-debugsourceUpgrade httpd-coreUpgrade mod_ldapUpgrade httpd-manualUpgrade mod_ssl | Jul 15, 2025 | Jul 10, 2025 |
| Rocky_linux | — | Upgrade mod_proxy_html-debuginfoUpgrade mod_http2Upgrade mod_luaUpgrade mod_session-debuginfoUpgrade httpd-coreUpgrade mod_ldapUpgrade httpd-core-debuginfoUpgrade mod_md-debuginfoUpgrade httpd-tools-debuginfoUpgrade mod_lua-debuginfoUpgrade mod_sessionUpgrade mod_http2-debugsourceUpgrade httpd-debugsourceUpgrade httpd-develUpgrade mod_mdUpgrade mod_ssl-debuginfoUpgrade httpd-debuginfoUpgrade mod_ldap-debuginfoUpgrade mod_md-debugsourceUpgrade mod_http2-debuginfoUpgrade mod_proxy_htmlUpgrade mod_sslUpgrade httpd-toolsUpgrade httpd | Feb 5, 2026 | Sep 8, 2025 |
| Suse | — | Upgrade apache2-utilsUpgrade apache2-tls13-docUpgrade apache2-docUpgrade apache2-tls13-develUpgrade apache2-example-pagesUpgrade apache2-manualUpgrade apache2-tls13-utilsUpgrade apache2-eventUpgrade apache2-tls13-workerUpgrade apache2-preforkUpgrade apache2-tls13Upgrade apache2-tls13-example-pagesUpgrade apache2-workerUpgrade apache2Upgrade apache2-develUpgrade apache2-tls13-prefork | Dec 5, 2025 | Sep 9, 2025 |
| Ubuntu | — | Upgrade apache2 (Ubuntu Pro)Upgrade apache2 | Jul 17, 2025 | Jul 10, 2025 |
| Vmware Photon_os | — | Use 'tdnf update' to upgrade all packages to the latest version. | Aug 11, 2025 | Jul 10, 2025 |
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