Description
A timing attack against mod_auth_digest in Apache HTTP Server 2.4.66 allows a bypass of Digest authentication by a remote attacker.
Users are recommended to upgrade to version 2.4.67, which fixes this issue.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Apache Software Foundation | Apache HTTP Server | ≤ 2.4.66 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | apache2 | 2.4.67-1 | — |
| Debian 13 | apache2 | 2.4.67-1~deb13u2 | — |
| Debian 12 | apache2 | 2.4.67-1~deb12u2 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.04 LTS | apache2 | 2.4.66-2ubuntu2.1 | — |
| Ubuntu 25.10 | apache2 | 2.4.64-1ubuntu3.4 | — |
| Ubuntu 24.04 LTS | apache2 | 2.4.58-1ubuntu8.12 | — |
| Ubuntu 22.04 LTS | apache2 | 2.4.52-1ubuntu4.20 | — |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 20.04 LTS | apache2 | 2.4.41-4ubuntu3.23+esm6 | USN-8589-1 |
| Ubuntu Pro 18.04 LTS | apache2 | 2.4.29-1ubuntu4.27+esm11 | USN-8589-1 |
| Ubuntu Pro 16.04 LTS | apache2 | 2.4.18-2ubuntu3.17+esm20 | USN-8589-1 |
| Ubuntu Pro 14.04 LTS | apache2 | 2.4.7-1ubuntu4.22+esm15 | USN-8589-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10 | httpd +8 | 2.4.63-13.el10_2.4 | RHSA-2026:34109 |
| RHEL 10 | mod_ssl +1 | 1:2.4.63-13.el10_2.4 | RHSA-2026:34109 |
| RHEL 9 | httpd +8 | 2.4.62-13.el9_8.5 | RHSA-2026:41906 |
| RHEL 9 | mod_ssl +1 | 1:2.4.62-13.el9_8.5 | RHSA-2026:41906 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat JBoss Core Services 1 | jbcs-httpd24-httpd +6 | 2.4.62-17.el8jbcs | RHSA-2026:73076 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-mod_http2 | 2.0.29-14.el8jbcs | RHSA-2026:73076 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-mod_jk +1 | 1.2.50-18.redhat_1.el8jbcs | RHSA-2026:73076 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-mod_md | 1:2.4.28-20.el8jbcs | RHSA-2026:73076 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-mod_proxy_cluster | 1.3.22-13.el8jbcs | RHSA-2026:73076 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-mod_security | 2.9.6-20.el8jbcs | RHSA-2026:73076 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-mod_ssl +1 | 1:2.4.62-17.el8jbcs | RHSA-2026:73076 |
| Red Hat Hardened Images 1 | httpd +5 | 2.4.67-1.hum1 | RHSA-2026:17080 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 10 | httpd +8 | 2.4.63-13.el10_2.4 | ALSA-2026:34109 |
| AlmaLinux 10 | mod_ssl +1 | 1:2.4.63-13.el10_2.4 | ALSA-2026:34109 |
| AlmaLinux 9 | httpd +8 | 2.4.62-13.el9_8.5 | ALSA-2026:41906 |
| AlmaLinux 9 | mod_ssl +1 | 1:2.4.62-13.el9_8.5 | ALSA-2026:41906 |
| AlmaLinux 8 | httpd +6 | 2.4.37-65.module_el8.10.0+4332+2bef2e0d.13 | ALSA-2026:92616 |
| AlmaLinux 8 | mod_http2 | 1.15.7-10.module_el8.10.0+4233+8b7d9181.7 | ALSA-2026:92616 |
| AlmaLinux 8 | mod_md | 1:2.0.8-8.module_el8.10.0+4295+280de5aa.4 | ALSA-2026:92616 |
| AlmaLinux 8 | mod_ssl +1 | 1:2.4.37-65.module_el8.10.0+4332+2bef2e0d.13 | ALSA-2026:92616 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 9 | httpd | 2.4.62-13.el9_8.5 | RLSA-2026:41906 |
| Rocky Linux 8 | httpd | 2.4.37-65.module+el8.10.0+1830+22f0c9e0 | RLSA-2026:92616 |
| Rocky Linux 8 | mod_http2 | 1.15.7-10.module+el8.10.0+1775+6b057638 | RLSA-2026:92616 |
| Rocky Linux 8 | mod_md | 1:2.0.8-8.module+el8.9.0+1370+89cc8ad5 | RLSA-2026:92616 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP5 | apache2 | 2.4.66-150400.6.57.1 | SUSE-SU-2026:2686-1 |
| SLES 15 SP4 | apache2 | 2.4.66-150400.6.57.1 | SUSE-SU-2026:2686-1 |
| SLES 12 SP5 | apache2 +1 | 2.4.66-35.78.1 | SUSE-SU-2026:2641-1 |
Show 6 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | apache2 +6 | 2.4.66-160000.2.1 | SUSE-SU-2026:22209-1, SUSE-SU-2026:22199-1 |
| SLES for SAP 15 SP5 | apache2 | 2.4.66-150400.6.57.1 | SUSE-SU-2026:2686-1 |
| SLES for SAP 15 SP4 | apache2 | 2.4.66-150400.6.57.1 | SUSE-SU-2026:2686-1 |
| SLES 16.0 | apache2 +6 | 2.4.66-160000.2.1 | SUSE-SU-2026:22209-1, SUSE-SU-2026:22199-1 |
| SLE HPC 15 SP5 | apache2 | 2.4.66-150400.6.57.1 | SUSE-SU-2026:2686-1 |
| SLE HPC 15 SP4 | apache2 | 2.4.66-150400.6.57.1 | SUSE-SU-2026:2686-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | apache2 | 2.4.67-1.1 | openSUSE-SU-2026:10785-1 |
| openSUSE Leap 16.0 | apache2 +6 | 2.4.66-160000.2.1 | openSUSE-SU-2026:21115-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | apache2 | 2.4.67-r0 | — |
| Alpine v3.23 | apache2 | 2.4.67-r0 | — |
| Alpine v3.22 | apache2 | 2.4.67-r0 | — |
| Alpine v3.21 | apache2 | 2.4.67-r0 | — |
| Alpine v3.20 | apache2 | 2.4.67-r0 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | httpd +8 | 2.4.67-1.amzn2023.0.1 | ALAS2023-2026-1720 |
| Amazon Linux 2023 | mod_ssl +1 | 1:2.4.67-1.amzn2023.0.1 | ALAS2023-2026-1720 |
| Amazon Linux 2 | httpd +7 | 2.4.67-1.amzn2.0.1 | ALAS2-2026-3314 |
| Amazon Linux 2 | mod_ssl +1 | 1:2.4.67-1.amzn2.0.1 | ALAS2-2026-3314 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | httpd | 2.4.67-1 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 9 | httpd +8 | 2.4.62-13.0.1.el9_8.5 | ELSA-2026-41906 |
| Oracle Linux 9 | mod_ssl +1 | 1:2.4.62-13.0.1.el9_8.5 | ELSA-2026-41906 |
| Oracle Linux 8 | httpd +6 | 2.4.37-65.0.1.module+el8.10.0+91092+d4ec9ae3.8 | ELSA-2026-92616 |
| Oracle Linux 8 | mod_http2 | 1.15.7-10.module+el8.10.0+91023+3994037c.7 | ELSA-2026-92616 |
| Oracle Linux 8 | mod_md | 1:2.0.8-8.module+el8.10.0+91092+d4ec9ae3.4 | ELSA-2026-92616 |
| Oracle Linux 8 | mod_ssl +1 | 1:2.4.37-65.0.1.module+el8.10.0+91092+d4ec9ae3.8 | ELSA-2026-92616 |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.
GitHub 1 repository
-
SimoesCTT/CTT-enhanced-Apache-mod_auth_digest-timing-attack-exploit ★ 0 · May 8, 2026
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_auth_di…
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 22
- WID-SEC-2026-1354 Apache HTTP Server: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 11, 2026
- RLSA-2026:92616 Important: httpd:2.4 security, bug fix, and enhancement update Rocky Linux Security Advisories · Oct 30, 2026
- ALSA-2026:92616 Important: httpd:2.4 security, bug fix, and enhancement update AlmaLinux Security Advisories · Oct 30, 2026
- ELSA-2026-92616 Important: httpd:2.4 security, bug fix, and enhancement update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Oct 30, 2026
- ALSA-2026:34109 Important: httpd security, bug fix, and enhancement update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:41906 Important: httpd security, bug fix, and enhancement update AlmaLinux Security Advisories · Oct 29, 2026
- RHSA-2026:41906 Red Hat Security Advisory: httpd security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- RHSA-2026:34109 Red Hat Security Advisory: httpd security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- RHSA-2026:17080 Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update Red Hat Security Advisories (RHSA) · Oct 9, 2026
- RHSA-2026:73076 Red Hat Security Advisory: Red Hat JBoss Core Services Apache HTTP Server 2.4.62 SP6 security update Red Hat Security Advisories (RHSA) · Oct 2, 2026
- SUSE-SU-2026:2641-1 Security update for apache2 SUSE / openSUSE Security Updates · Aug 27, 2026
- USN-8589-1 apache2 vulnerabilities Ubuntu Security Notices (USN) · Jul 23, 2026
- RLSA-2026:41906 Important: httpd security, bug fix, and enhancement update Rocky Linux Security Advisories · Jul 22, 2026
- ELSA-2026-41906 Important: httpd security, bug fix, and enhancement update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Jul 20, 2026
- SUSE-SU-2026:2686-1 Security update for apache2 SUSE / openSUSE Security Updates · Jul 1, 2026
- openSUSE-SU-2026:21115-1 Security update for apache2 SUSE / openSUSE Security Updates · Jun 30, 2026
- SUSE-SU-2026:22209-1 Security update for apache2 SUSE / openSUSE Security Updates · Jun 24, 2026
- SUSE-SU-2026:22199-1 Security update for apache2 SUSE / openSUSE Security Updates · Jun 24, 2026
- ALAS2-2026-3314 Important: httpd security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · May 26, 2026
- ALAS2023-2026-1720 Important: httpd security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · May 26, 2026
- openSUSE-SU-2026:10785-1 apache2-2.4.67-1.1 on GA media SUSE / openSUSE Security Updates · May 17, 2026
- NCSC-2026-0134 Kwetsbaarheden verholpen in Apache HTTP Server NCSC-NL (Netherlands) · May 6, 2026
References
- https://httpd.apache.org/security/vulnerabilities_24.html vendor-advisory