CVE-2026-33523
Fixed in a distro release EPSS <1%CVSS 6.5
HTTP response splitting vulnerability in multiple Apache HTTP Server modules with untrusted or compromised backend servers. This issue affects Apache HTTP Server: from through 2.4.66. Users are recommended to upgrade to version 2.4.67, which fixes the issue.
Products: Apache Software Foundation Apache HTTP Server
Distro releases
| Release | Package | Fixed in |
|---|---|---|
| Alpine 3.20 | apache2 | 2.4.67-r0 |
| Alpine 3.21 | apache2 | 2.4.67-r0 |
| Alpine 3.22 | apache2 | 2.4.67-r0 |
| Alpine 3.23 | apache2 | 2.4.67-r0 |
| Alpine 3.24 | apache2 | 2.4.67-r0 |
| Amazon Linux 2 | httpd | 2.4.67-1.amzn2.0.1 |
| Amazon Linux 2 | httpd-devel | 2.4.67-1.amzn2.0.1 |
| Amazon Linux 2 | httpd-filesystem | 2.4.67-1.amzn2.0.1 |
| Amazon Linux 2 | httpd-manual | 2.4.67-1.amzn2.0.1 |
| Amazon Linux 2 | httpd-tools | 2.4.67-1.amzn2.0.1 |
| Amazon Linux 2 | mod_ldap | 2.4.67-1.amzn2.0.1 |
| Amazon Linux 2 | mod_md | 2.4.67-1.amzn2.0.1 |
| Amazon Linux 2 | mod_proxy_html | 1:2.4.67-1.amzn2.0.1 |
| Amazon Linux 2 | mod_session | 2.4.67-1.amzn2.0.1 |
| Amazon Linux 2 | mod_ssl | 1:2.4.67-1.amzn2.0.1 |
| Amazon Linux 2023 | httpd | 2.4.67-1.amzn2023.0.1 |
| Amazon Linux 2023 | httpd-core | 2.4.67-1.amzn2023.0.1 |
| Amazon Linux 2023 | httpd-devel | 2.4.67-1.amzn2023.0.1 |
| Amazon Linux 2023 | httpd-filesystem | 2.4.67-1.amzn2023.0.1 |
| Amazon Linux 2023 | httpd-manual | 2.4.67-1.amzn2023.0.1 |
| Amazon Linux 2023 | httpd-tools | 2.4.67-1.amzn2023.0.1 |
| Amazon Linux 2023 | mod_ldap | 2.4.67-1.amzn2023.0.1 |
| Amazon Linux 2023 | mod_lua | 2.4.67-1.amzn2023.0.1 |
| Amazon Linux 2023 | mod_proxy_html | 1:2.4.67-1.amzn2023.0.1 |
| Amazon Linux 2023 | mod_session | 2.4.67-1.amzn2023.0.1 |
| Amazon Linux 2023 | mod_ssl | 1:2.4.67-1.amzn2023.0.1 |
| Debian 12 | apache2 | 2.4.67-1~deb12u2 |
| Debian 13 | apache2 | 2.4.67-1~deb13u2 |
| Debian 14 | apache2 | 2.4.67-1 |
| Red Hat hummingbird 1 | httpd | 0:2.4.67-1.hum1 |
| Red Hat hummingbird 1 | httpd-core | 0:2.4.67-1.hum1 |
| Red Hat hummingbird 1 | httpd-devel | 0:2.4.67-1.hum1 |
| Red Hat hummingbird 1 | httpd-filesystem | 0:2.4.67-1.hum1 |
| Red Hat hummingbird 1 | httpd-manual | 0:2.4.67-1.hum1 |
| Red Hat hummingbird 1 | httpd-tools | 0:2.4.67-1.hum1 |
| Red Hat jboss core services 1 | jbcs-httpd24-httpd | 0:2.4.62-17.el8jbcs |
| Red Hat jboss core services 1 | jbcs-httpd24-httpd-debuginfo | 0:2.4.62-17.el8jbcs |
| Red Hat jboss core services 1 | jbcs-httpd24-httpd-devel | 0:2.4.62-17.el8jbcs |
| Red Hat jboss core services 1 | jbcs-httpd24-httpd-manual | 0:2.4.62-17.el8jbcs |
| Red Hat jboss core services 1 | jbcs-httpd24-httpd-selinux | 0:2.4.62-17.el8jbcs |
| Red Hat jboss core services 1 | jbcs-httpd24-httpd-tools | 0:2.4.62-17.el8jbcs |
| Red Hat jboss core services 1 | jbcs-httpd24-httpd-tools-debuginfo | 0:2.4.62-17.el8jbcs |
| Red Hat jboss core services 1 | jbcs-httpd24-mod_http2 | 0:2.0.29-14.el8jbcs |
| Red Hat jboss core services 1 | jbcs-httpd24-mod_http2-debuginfo | 0:2.0.29-14.el8jbcs |
| Red Hat jboss core services 1 | jbcs-httpd24-mod_jk | 0:1.2.50-18.redhat_1.el8jbcs |
| Red Hat jboss core services 1 | jbcs-httpd24-mod_jk-ap24 | 0:1.2.50-18.redhat_1.el8jbcs |
| Red Hat jboss core services 1 | jbcs-httpd24-mod_jk-ap24-debuginfo | 0:1.2.50-18.redhat_1.el8jbcs |
| Red Hat jboss core services 1 | jbcs-httpd24-mod_ldap | 0:2.4.62-17.el8jbcs |
| Red Hat jboss core services 1 | jbcs-httpd24-mod_ldap-debuginfo | 0:2.4.62-17.el8jbcs |
| Red Hat jboss core services 1 | jbcs-httpd24-mod_md | 1:2.4.28-20.el8jbcs |
| Red Hat jboss core services 1 | jbcs-httpd24-mod_md-debuginfo | 1:2.4.28-20.el8jbcs |
| Red Hat jboss core services 1 | jbcs-httpd24-mod_proxy_cluster | 0:1.3.22-13.el8jbcs |
| Red Hat jboss core services 1 | jbcs-httpd24-mod_proxy_cluster-debuginfo | 0:1.3.22-13.el8jbcs |
| Red Hat jboss core services 1 | jbcs-httpd24-mod_proxy_html | 1:2.4.62-17.el8jbcs |
| Red Hat jboss core services 1 | jbcs-httpd24-mod_proxy_html-debuginfo | 1:2.4.62-17.el8jbcs |
| Red Hat jboss core services 1 | jbcs-httpd24-mod_security | 0:2.9.6-20.el8jbcs |
| Red Hat jboss core services 1 | jbcs-httpd24-mod_security-debuginfo | 0:2.9.6-20.el8jbcs |
| Red Hat jboss core services 1 | jbcs-httpd24-mod_session | 0:2.4.62-17.el8jbcs |
| Red Hat jboss core services 1 | jbcs-httpd24-mod_session-debuginfo | 0:2.4.62-17.el8jbcs |
| Red Hat jboss core services 1 | jbcs-httpd24-mod_ssl | 1:2.4.62-17.el8jbcs |
| Red Hat jboss core services 1 | jbcs-httpd24-mod_ssl-debuginfo | 1:2.4.62-17.el8jbcs |
| SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS | apache2 | 2.4.66-150400.6.57.1 |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | apache2 | 2.4.66-150400.6.57.1 |
| SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS | apache2 | 2.4.66-150400.6.57.1 |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | apache2 | 2.4.66-150400.6.57.1 |
| SUSE Linux Enterprise Server 12 SP5-LTSS | apache2 | 2.4.66-35.78.1 |
| SUSE Linux Enterprise Server 12 SP5-LTSS | apache2-tls13 | 2.4.66-35.78.1 |
| SUSE Linux Enterprise Server 15 SP4-LTSS | apache2 | 2.4.66-150400.6.57.1 |
| SUSE Linux Enterprise Server 15 SP5-LTSS | apache2 | 2.4.66-150400.6.57.1 |
| SUSE Linux Enterprise Server 16.0 | apache2 | 2.4.66-160000.2.1 |
| SUSE Linux Enterprise Server 16.0 | apache2-devel | 2.4.66-160000.2.1 |
| SUSE Linux Enterprise Server 16.0 | apache2-event | 2.4.66-160000.2.1 |
| SUSE Linux Enterprise Server 16.0 | apache2-manual | 2.4.66-160000.2.1 |
| SUSE Linux Enterprise Server 16.0 | apache2-prefork | 2.4.66-160000.2.1 |
| SUSE Linux Enterprise Server 16.0 | apache2-utils | 2.4.66-160000.2.1 |
| SUSE Linux Enterprise Server 16.0 | apache2-worker | 2.4.66-160000.2.1 |
| SUSE Linux Enterprise Server LTSS Extended Security 12 SP5 | apache2 | 2.4.66-35.78.1 |
| SUSE Linux Enterprise Server LTSS Extended Security 12 SP5 | apache2-tls13 | 2.4.66-35.78.1 |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | apache2 | 2.4.66-150400.6.57.1 |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | apache2 | 2.4.66-150400.6.57.1 |
| SUSE Linux Enterprise Server for SAP applications 16.0 | apache2 | 2.4.66-160000.2.1 |
| SUSE Linux Enterprise Server for SAP applications 16.0 | apache2-devel | 2.4.66-160000.2.1 |
| SUSE Linux Enterprise Server for SAP applications 16.0 | apache2-event | 2.4.66-160000.2.1 |
| SUSE Linux Enterprise Server for SAP applications 16.0 | apache2-manual | 2.4.66-160000.2.1 |
| SUSE Linux Enterprise Server for SAP applications 16.0 | apache2-prefork | 2.4.66-160000.2.1 |
| SUSE Linux Enterprise Server for SAP applications 16.0 | apache2-utils | 2.4.66-160000.2.1 |
| SUSE Linux Enterprise Server for SAP applications 16.0 | apache2-worker | 2.4.66-160000.2.1 |
| Ubuntu 22.04 LTS | apache2 | 2.4.52-1ubuntu4.20 |
| Ubuntu 24.04 LTS | apache2 | 2.4.58-1ubuntu8.12 |
| Ubuntu 25.10 | apache2 | 2.4.64-1ubuntu3.4 |
| Ubuntu 26.04 LTS | apache2 | 2.4.66-2ubuntu2.1 |
| Ubuntu Pro 14.04 LTS | apache2 | 2.4.7-1ubuntu4.22+esm14 |
| Ubuntu Pro 16.04 LTS | apache2 | 2.4.18-2ubuntu3.17+esm19 |
| Ubuntu Pro 18.04 LTS | apache2 | 2.4.29-1ubuntu4.27+esm10 |
| Ubuntu Pro 20.04 LTS | apache2 | 2.4.41-4ubuntu3.23+esm5 |
| openSUSE Leap 16.0 | apache2 | 2.4.66-160000.2.1 |
| openSUSE Leap 16.0 | apache2-devel | 2.4.66-160000.2.1 |
| openSUSE Leap 16.0 | apache2-event | 2.4.66-160000.2.1 |
| openSUSE Leap 16.0 | apache2-manual | 2.4.66-160000.2.1 |
| openSUSE Leap 16.0 | apache2-prefork | 2.4.66-160000.2.1 |
| openSUSE Leap 16.0 | apache2-utils | 2.4.66-160000.2.1 |
| openSUSE Leap 16.0 | apache2-worker | 2.4.66-160000.2.1 |
| openSUSE Tumbleweed | apache2 | 2.4.67-1.1 |