NULL pointer dereference in Apache HTTP Server - CVE-2026-33007

Vulnerability identifier: #VU129544

CSH Severity: Medium

CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-33007

CWE-ID: CWE-476

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to a NULL pointer dereference in mod_authn_socache when handling requests in a caching forward proxy configuration. A remote attacker can send a malicious request to cause a denial of service.

The issue crashes a child process only in a caching forward proxy configuration.

Apache HTTP Server
SUSE Linux Enterprise Server 15 SP6
Debian Linux
SUSE Linux Enterprise Server 15 SP4
SUSE Linux Enterprise Server 12 SP5 LTSS Extended
SUSE Linux Enterprise Server 12 SP5
SUSE Linux Enterprise Server 15 SP5
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise High Performance Computing LTSS 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise High Performance Computing ESPOS 15
SUSE Linux Enterprise High Performance Computing 15
SUSE Linux Enterprise Server 12
SUSE Linux Enterprise Server for SAP Applications 12
SUSE Linux Enterprise High Performance Computing 12
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise Real Time 15
Anolis OS
Red Hat Enterprise Linux Server - AUS
Red Hat Enterprise Linux Server - TUS
Red Hat Enterprise Linux for ARM 64 - Extended Update Support
Red Hat Enterprise Linux for x86_64 - Extended Update Support
Red Hat Enterprise Linux for IBM z Systems - Extended Update Support
Red Hat Enterprise Linux for Power, little endian - Extended Update Support
Red Hat Enterprise Linux for ARM 64
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for x86_64
Ubuntu
SUSE Package Hub 15
Server Applications Module
Basesystem Module
openSUSE Leap
openEuler
Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions
mod_http2
mod_md
apache2 (Ubuntu package)
httpd
httpd-manual
httpd-filesystem
mod_ssl
mod_session
mod_ldap
httpd-tools
httpd-devel
mod_proxy_html
httpd-debuginfo
httpd-debugsource
httpd-help
httpd (Red Hat package)
apache2-example-pages
apache2-tls13-devel
apache2-prefork-debuginfo
apache2-worker
apache2-tls13-prefork-debuginfo
apache2-prefork
apache2-devel
apache2-debugsource
apache2-tls13-worker-debuginfo
apache2-utils-debuginfo
apache2-tls13-example-pages
apache2
apache2-debuginfo
apache2-tls13-worker
apache2-tls13-debugsource
apache2-tls13-debuginfo
apache2-tls13
apache2-tls13-utils-debuginfo
apache2-utils
apache2-tls13-prefork
apache2-tls13-utils
apache2-worker-debuginfo
apache2-doc
apache2-tls13-doc
apache2-event-debuginfo
apache2-event
apache2-manual
apache2-prefork-debugsource
apache2-utils-debugsource
apache2-worker-debugsource
apache2-event-debugsource
apache2 (Debian package)

Install security update from vendor's website.

Apache HTTP Server - update to 2.4.67
mod_http2 - update to 1.15.7-10
mod_md - update to 2.0.8-8
apache2 (Ubuntu package) - addressed in versions 2.4.7-1ubuntu4.22+esm14, 2.4.18-2ubuntu3.17+esm19, 2.4.29-1ubuntu4.27+esm10, 2.4.41-4ubuntu3.23+esm5, 2.4.52-1ubuntu4.20, 2.4.58-1ubuntu8.12, 2.4.64-1ubuntu3.4, 2.4.66-2ubuntu2.1
httpd - update to 2.4.37-655.0.1
httpd-manual - update to 2.4.37-655.0.1
httpd-filesystem - update to 2.4.37-655.0.1
mod_ssl - update to 2.4.37-655.0.1
mod_session - update to 2.4.37-655.0.1
mod_ldap - update to 2.4.37-655.0.1
httpd-tools - update to 2.4.37-655.0.1
httpd-devel - update to 2.4.37-655.0.1
mod_proxy_html - update to 2.4.37-655.0.1
httpd - addressed in versions 2.4.43-35, 2.4.51-30, 2.4.58-15
httpd-debuginfo - addressed in versions 2.4.43-35, 2.4.51-30, 2.4.58-15
httpd-debugsource - addressed in versions 2.4.43-35, 2.4.51-30, 2.4.58-15
httpd-devel - addressed in versions 2.4.43-35, 2.4.51-30, 2.4.58-15
httpd-tools - addressed in versions 2.4.43-35, 2.4.51-30, 2.4.58-15
mod_ldap - addressed in versions 2.4.43-35, 2.4.51-30, 2.4.58-15
mod_md - addressed in versions 2.4.43-35, 2.4.51-30, 2.4.58-15
mod_proxy_html - addressed in versions 2.4.43-35, 2.4.51-30, 2.4.58-15
mod_session - addressed in versions 2.4.43-35, 2.4.51-30, 2.4.58-15
mod_ssl - addressed in versions 2.4.43-35, 2.4.51-30, 2.4.58-15
httpd-help - addressed in versions 2.4.43-35, 2.4.51-30, 2.4.58-15
httpd-filesystem - addressed in versions 2.4.43-35, 2.4.51-30, 2.4.58-15
httpd (Red Hat package) - addressed in versions 2.4.63-1.el10_0.4, 2.4.63-13.el10_2.1
apache2-example-pages - addressed in versions 2.4.66-35.78.1, 2.4.66-150400.6.57.1
apache2-tls13-devel - update to 2.4.66-35.78.1
apache2-prefork-debuginfo - addressed in versions 2.4.66-35.78.1, 2.4.66-150400.6.57.1, 2.4.66-150600.5.52.1, 2.4.66-150700.4.20.1
apache2-worker - addressed in versions 2.4.66-35.78.1, 2.4.66-150400.6.57.1, 2.4.66-150600.5.52.1, 2.4.66-150700.4.20.1
apache2-tls13-prefork-debuginfo - update to 2.4.66-35.78.1
apache2-prefork - addressed in versions 2.4.66-35.78.1, 2.4.66-150400.6.57.1, 2.4.66-150600.5.52.1, 2.4.66-150700.4.20.1
apache2-devel - addressed in versions 2.4.66-35.78.1, 2.4.66-150400.6.57.1, 2.4.66-150600.5.52.1, 2.4.66-150700.4.20.1
apache2-debugsource - addressed in versions 2.4.66-35.78.1, 2.4.66-150400.6.57.1, 2.4.66-150600.5.52.1, 2.4.66-150700.4.20.1
apache2-tls13-worker-debuginfo - update to 2.4.66-35.78.1
apache2-utils-debuginfo - addressed in versions 2.4.66-35.78.1, 2.4.66-150400.6.57.1, 2.4.66-150600.5.52.1, 2.4.66-150700.4.20.1
apache2-tls13-example-pages - update to 2.4.66-35.78.1
apache2 - addressed in versions 2.4.66-35.78.1, 2.4.66-150400.6.57.1, 2.4.66-150600.5.52.1, 2.4.66-150700.4.20.1
apache2-debuginfo - addressed in versions 2.4.66-35.78.1, 2.4.66-150400.6.57.1, 2.4.66-150600.5.52.1, 2.4.66-150700.4.20.1
apache2-tls13-worker - update to 2.4.66-35.78.1
apache2-tls13-debugsource - update to 2.4.66-35.78.1
apache2-tls13-debuginfo - update to 2.4.66-35.78.1
apache2-tls13 - update to 2.4.66-35.78.1
apache2-tls13-utils-debuginfo - update to 2.4.66-35.78.1
apache2-utils - addressed in versions 2.4.66-35.78.1, 2.4.66-150400.6.57.1, 2.4.66-150600.5.52.1, 2.4.66-150700.4.20.1
apache2-tls13-prefork - update to 2.4.66-35.78.1
apache2-tls13-utils - update to 2.4.66-35.78.1
apache2-worker-debuginfo - addressed in versions 2.4.66-35.78.1, 2.4.66-150400.6.57.1, 2.4.66-150600.5.52.1, 2.4.66-150700.4.20.1
apache2-doc - addressed in versions 2.4.66-35.78.1, 2.4.66-150400.6.57.1
apache2-tls13-doc - update to 2.4.66-35.78.1
apache2-event-debuginfo - addressed in versions 2.4.66-150400.6.57.1, 2.4.66-150600.5.52.1, 2.4.66-150700.4.20.1
apache2-event - addressed in versions 2.4.66-150400.6.57.1, 2.4.66-150600.5.52.1, 2.4.66-150700.4.20.1
apache2-manual - addressed in versions 2.4.66-150600.5.52.1, 2.4.66-150700.4.20.1
apache2-prefork-debugsource - addressed in versions 2.4.66-150600.5.52.1, 2.4.66-150700.4.20.1
apache2-utils-debugsource - addressed in versions 2.4.66-150600.5.52.1, 2.4.66-150700.4.20.1
apache2-worker-debugsource - addressed in versions 2.4.66-150600.5.52.1, 2.4.66-150700.4.20.1
apache2-event-debugsource - addressed in versions 2.4.66-150600.5.52.1, 2.4.66-150700.4.20.1
apache2 (Debian package) - addressed in versions 2.4.67-1~deb12u2, 2.4.67-1~deb13u2

• https://httpd.apache.org/security/vulnerabilities_24.html#CVE-2026-33007
• https://lists.apache.org/thread/4qokdcgl8q6tl3b594v72sr52g7wrbd4

• Multiple vulnerabilities in Apache HTTP Server
• Ubuntu update for apache2
• Debian update for apache2
• openEuler 24.03 LTS SP1 update for httpd
• openEuler 22.03 LTS SP4 update for httpd
• openEuler 20.03 LTS SP4 update for httpd
• openEuler 24.03 LTS SP3 update for httpd
• openEuler 24.03 LTS update for httpd
• Red Hat Enterprise Linux 10 update for httpd
• SUSE update for apache2
• SUSE update for apache2
• Anolis OS update for httpd:2.4 module
• SUSE update for apache2
• SUSE update for apache2
• Red Hat Enterprise Linux 8 update for the httpd:2.4 module
• Red Hat Enterprise Linux 8 update for the httpd:2.4 module
• Red Hat Enterprise Linux 8 update for the httpd:2.4 module
• Ubuntu update for apache2
• Red Hat Enterprise Linux 10 update for httpd