In certain proxy configurations, a denial of service attack against Apache HTTP Server versions 2.4.26 through to 2.4.63 can be triggered by untrusted clients causing an assertion in mod_proxy_http2.
Configurations affected are a reverse proxy is configured for an HTTP/2 backend, with ProxyPreserveHost set to "on".
CVSS Details
- CVSS 3.1 Base Score: 7.5
- CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Alma_linux | alma-upgrade-httpdalma-upgrade-httpd-develalma-upgrade-httpd-filesystemalma-upgrade-httpd-manualalma-upgrade-httpd-toolsalma-upgrade-mod_http2alma-upgrade-mod_ldapalma-upgrade-mod_mdalma-upgrade-mod_proxy_htmlalma-upgrade-mod_sessionalma-upgrade-mod_ssl | Sep 3, 2025 | Sep 2, 2025 | |
| Alpine Linux | alpine-linux-upgrade-apache2 | Aug 8, 2025 | Jul 10, 2025 | |
| Amazon Linux Ami 2 | amazon-linux-ami-2-upgrade-httpdamazon-linux-ami-2-upgrade-httpd-debuginfoamazon-linux-ami-2-upgrade-httpd-develamazon-linux-ami-2-upgrade-httpd-filesystemamazon-linux-ami-2-upgrade-httpd-manualamazon-linux-ami-2-upgrade-httpd-toolsamazon-linux-ami-2-upgrade-mod_ldapamazon-linux-ami-2-upgrade-mod_mdamazon-linux-ami-2-upgrade-mod_proxy_htmlamazon-linux-ami-2-upgrade-mod_sessionamazon-linux-ami-2-upgrade-mod_ssl | May 20, 2026 | May 20, 2026 | |
| Amazon_linux_2023 | amazon-linux-2023-upgrade-httpdamazon-linux-2023-upgrade-httpd-coreamazon-linux-2023-upgrade-httpd-core-debuginfoamazon-linux-2023-upgrade-httpd-debuginfoamazon-linux-2023-upgrade-httpd-debugsourceamazon-linux-2023-upgrade-httpd-develamazon-linux-2023-upgrade-httpd-filesystemamazon-linux-2023-upgrade-httpd-manualamazon-linux-2023-upgrade-httpd-toolsamazon-linux-2023-upgrade-httpd-tools-debuginfoamazon-linux-2023-upgrade-mod-ldapamazon-linux-2023-upgrade-mod-ldap-debuginfoamazon-linux-2023-upgrade-mod-luaamazon-linux-2023-upgrade-mod-lua-debuginfoamazon-linux-2023-upgrade-mod-proxy-htmlamazon-linux-2023-upgrade-mod-proxy-html-debuginfoamazon-linux-2023-upgrade-mod-sessionamazon-linux-2023-upgrade-mod-session-debuginfoamazon-linux-2023-upgrade-mod-sslamazon-linux-2023-upgrade-mod-ssl-debuginfo | Aug 5, 2025 | Jul 14, 2025 | |
| Apache Httpd | apache-httpd-upgrade-latest | Jul 18, 2025 | Jul 10, 2025 | |
| Debian | debian-upgrade-apache2 | Jul 14, 2025 | Jul 10, 2025 | |
| Freebsd | freebsd-upgrade-package-mod_http2freebsd-upgrade-package-apache24 | Jul 13, 2025 | Jul 11, 2025 | |
| Huawei Euleros 2_0_sp10 | huawei-euleros-2_0_sp10-upgrade-mod_http2 | Nov 12, 2025 | Oct 23, 2025 | |
| Huawei Euleros 2_0_sp11 | huawei-euleros-2_0_sp11-upgrade-mod_http2 | Dec 12, 2025 | Oct 23, 2025 | |
| Huawei Euleros 2_0_sp12 | huawei-euleros-2_0_sp12-upgrade-mod_http2 | Nov 12, 2025 | Oct 23, 2025 | |
| Huawei Euleros 2_0_sp13 | huawei-euleros-2_0_sp13-upgrade-httpdhuawei-euleros-2_0_sp13-upgrade-httpd-filesystemhuawei-euleros-2_0_sp13-upgrade-httpd-toolshuawei-euleros-2_0_sp13-upgrade-mod_ssl | Oct 24, 2025 | Oct 23, 2025 | |
| Oracle_linux | — | oracle-linux-upgrade-httpdoracle-linux-upgrade-httpd-develoracle-linux-upgrade-httpd-filesystemoracle-linux-upgrade-httpd-manualoracle-linux-upgrade-httpd-toolsoracle-linux-upgrade-mod-http2oracle-linux-upgrade-mod-ldaporacle-linux-upgrade-mod-mdoracle-linux-upgrade-mod-proxy-htmloracle-linux-upgrade-mod-sessionoracle-linux-upgrade-mod-ssl | Aug 27, 2025 | Jul 14, 2025 |
| Redhat_linux | redhat-upgrade-httpdredhat-upgrade-httpd-debuginforedhat-upgrade-httpd-debugsourceredhat-upgrade-httpd-develredhat-upgrade-httpd-filesystemredhat-upgrade-httpd-manualredhat-upgrade-httpd-toolsredhat-upgrade-httpd-tools-debuginforedhat-upgrade-mod_http2redhat-upgrade-mod_http2-debuginforedhat-upgrade-mod_http2-debugsourceredhat-upgrade-mod_ldapredhat-upgrade-mod_ldap-debuginforedhat-upgrade-mod_mdredhat-upgrade-mod_md-debuginforedhat-upgrade-mod_md-debugsourceredhat-upgrade-mod_proxy_htmlredhat-upgrade-mod_proxy_html-debuginforedhat-upgrade-mod_sessionredhat-upgrade-mod_session-debuginforedhat-upgrade-mod_sslredhat-upgrade-mod_ssl-debuginfo | Jul 15, 2025 | Jul 10, 2025 | |
| Rocky_linux | rocky-upgrade-httpdrocky-upgrade-httpd-debuginforocky-upgrade-httpd-debugsourcerocky-upgrade-httpd-develrocky-upgrade-httpd-toolsrocky-upgrade-httpd-tools-debuginforocky-upgrade-mod_http2rocky-upgrade-mod_http2-debuginforocky-upgrade-mod_http2-debugsourcerocky-upgrade-mod_ldaprocky-upgrade-mod_ldap-debuginforocky-upgrade-mod_mdrocky-upgrade-mod_md-debuginforocky-upgrade-mod_md-debugsourcerocky-upgrade-mod_proxy_htmlrocky-upgrade-mod_proxy_html-debuginforocky-upgrade-mod_sessionrocky-upgrade-mod_session-debuginforocky-upgrade-mod_sslrocky-upgrade-mod_ssl-debuginfo | Feb 5, 2026 | Sep 8, 2025 | |
| Suse | — | suse-upgrade-apache2suse-upgrade-apache2-develsuse-upgrade-apache2-docsuse-upgrade-apache2-eventsuse-upgrade-apache2-example-pagessuse-upgrade-apache2-manualsuse-upgrade-apache2-preforksuse-upgrade-apache2-tls13suse-upgrade-apache2-tls13-develsuse-upgrade-apache2-tls13-docsuse-upgrade-apache2-tls13-example-pagessuse-upgrade-apache2-tls13-preforksuse-upgrade-apache2-tls13-utilssuse-upgrade-apache2-tls13-workersuse-upgrade-apache2-utilssuse-upgrade-apache2-worker | Dec 5, 2025 | Sep 2, 2025 |
| Ubuntu | ubuntu-pro-upgrade-apache2ubuntu-upgrade-apache2 | Jul 17, 2025 | Jul 10, 2025 | |
| Vmware Photon_os | vmware-photon_os_update_tdnf | Aug 11, 2025 | Jul 10, 2025 |
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