Information Exposure Through Timing Discrepancy in Apache HTTP Server - CVE-2026-33006

Vulnerability identifier: #VU129545

CSH Severity: High

CVSS v4: 7 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:H/SI:H/SA:N]

CVE-ID: CVE-2026-33006

CWE-ID: CWE-208

Exploitation vector: Remote access

Exploit availability: Public exploit is available

The vulnerability allows a remote attacker to bypass Digest authentication.

The vulnerability exists due to a timing side-channel in mod_auth_digest when processing Digest authentication. A remote attacker can perform a timing attack to bypass Digest authentication.

Apache HTTP Server
SUSE Linux Enterprise Server 15 SP5
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 SP6
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise High Performance Computing LTSS 15
SUSE Linux Enterprise High Performance Computing 15
SUSE Linux Enterprise High Performance Computing ESPOS 15
SUSE Linux Enterprise Server for SAP Applications 12
SUSE Linux Enterprise Server 12
SUSE Linux Enterprise High Performance Computing 12
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise Real Time 15
Ubuntu
SUSE Package Hub 15
Server Applications Module
Basesystem Module
openSUSE Leap
openEuler
apache2 (Ubuntu package)
httpd-help
httpd-filesystem
mod_ssl
mod_session
mod_proxy_html
mod_md
mod_ldap
httpd-tools
httpd-devel
httpd-debugsource
httpd-debuginfo
httpd
apache2-example-pages
apache2-prefork
apache2-prefork-debuginfo
apache2-worker
apache2-tls13-prefork-debuginfo
apache2-tls13-devel
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-utils-debugsource
apache2-worker-debugsource
apache2-event-debugsource
apache2-prefork-debugsource
apache2-manual
apache2 (Debian package)

Install security update from vendor's website.

Apache HTTP Server - update to 2.4.67
apache2 (Ubuntu package) - addressed in versions 2.4.7-1ubuntu4.22+esm15, 2.4.18-2ubuntu3.17+esm20, 2.4.29-1ubuntu4.27+esm11, 2.4.41-4ubuntu3.23+esm6, 2.4.52-1ubuntu4.20, 2.4.58-1ubuntu8.12, 2.4.64-1ubuntu3.4, 2.4.66-2ubuntu2.1
httpd-help - addressed in versions 2.4.43-35, 2.4.51-29, 2.4.58-14, 2.4.58-15
httpd-filesystem - addressed in versions 2.4.43-35, 2.4.51-29, 2.4.58-14, 2.4.58-15
mod_ssl - addressed in versions 2.4.43-35, 2.4.51-29, 2.4.58-14, 2.4.58-15
mod_session - addressed in versions 2.4.43-35, 2.4.51-29, 2.4.58-14, 2.4.58-15
mod_proxy_html - addressed in versions 2.4.43-35, 2.4.51-29, 2.4.58-14, 2.4.58-15
mod_md - addressed in versions 2.4.43-35, 2.4.51-29, 2.4.58-14, 2.4.58-15
mod_ldap - addressed in versions 2.4.43-35, 2.4.51-29, 2.4.58-14, 2.4.58-15
httpd-tools - addressed in versions 2.4.43-35, 2.4.51-29, 2.4.58-14, 2.4.58-15
httpd-devel - addressed in versions 2.4.43-35, 2.4.51-29, 2.4.58-14, 2.4.58-15
httpd-debugsource - addressed in versions 2.4.43-35, 2.4.51-29, 2.4.58-14, 2.4.58-15
httpd-debuginfo - addressed in versions 2.4.43-35, 2.4.51-29, 2.4.58-14, 2.4.58-15
httpd - addressed in versions 2.4.43-35, 2.4.51-29, 2.4.58-14, 2.4.58-15
apache2-example-pages - addressed in versions 2.4.66-35.78.1, 2.4.66-150400.6.57.1
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-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-tls13-devel - update to 2.4.66-35.78.1
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-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-prefork-debugsource - addressed in versions 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 (Debian package) - addressed in versions 2.4.67-1~deb12u2, 2.4.67-1~deb13u2

• Exploit #12727 - CTT-enhanced-Apache-mod_auth_digest-timing-attack-exploit (CTT-Enhanced Apache mod_auth_digest Timing Attack — CVE-2026-33006 Remote Digest Authentication Bypass → 33-Layer Temporal Timing Attack Original vulnerability: Apache HTTP Server 2.4.66 (mod_aut (May 22, 2026)

• https://httpd.apache.org/security/vulnerabilities_24.html#CVE-2026-33006
• https://lists.apache.org/thread/ro2mhvozhdp1j5d8w68nwgyzr9fy2s7y

• Multiple vulnerabilities in Apache HTTP Server
• Ubuntu update for apache2
• Debian update for apache2
• openEuler 24.03 LTS SP1 update for httpd
• openEuler 24.03 LTS update for httpd
• openEuler 22.03 LTS SP4 update for httpd
• openEuler 24.03 LTS SP3 update for httpd
• openEuler 20.03 LTS SP4 update for httpd
• SUSE update for apache2
• SUSE update for apache2
• SUSE update for apache2
• SUSE update for apache2
• Ubuntu update for apache2