Description
Allocation of Resources Without Limits or Throttling vulnerability in Apache HTTP Server's mod_md via OCSP response data.
This issue affects Apache HTTP Server: from 2.4.30 through 2.4.66.
Users are recommended to upgrade to version 2.4.67, which fixes the issue.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Apache Software Foundation | Apache HTTP Server | 2.4.30 – ≤ 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 | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10 | mod_md | 1:2.4.26-5.el10_2.1 | RHSA-2026:30845 |
| RHEL 9 | mod_md | 1:2.4.26-2.el9_8.1 | RHSA-2026:30844 |
Show 6 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10.0 EUS | mod_md | 1:2.4.26-3.el10_0.2 | RHSA-2026:52393 |
| RHEL 9.6 EUS | mod_md | 1:2.4.26-1.el9_6.2 | RHSA-2026:57641 |
| RHEL 9.4 E4S | mod_md | 1:2.4.19-1.el9_4.2 | RHSA-2026:57844 |
| RHEL 9.2 E4S | mod_md | 1:2.4.19-1.el9_2.2 | RHSA-2026:57642 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-httpd +6 | 2.4.62-13.el7jbcs | RHSA-2026:27200 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-mod_http2 | 2.0.29-10.el7jbcs | RHSA-2026:27200 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-mod_md | 1:2.4.28-16.el7jbcs | RHSA-2026:27200 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-mod_ssl +1 | 1:2.4.62-13.el7jbcs | RHSA-2026:27200 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-nghttp2 +1 | 1.64.0-3.el7jbcs | RHSA-2026:27200 |
| Red Hat Hardened Images 1 | httpd +10 | 2.4.68-6.hum1 | RHSA-2026:53537 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 10 | mod_md | 1:2.4.26-5.el10_2.1 | ALSA-2026:30845 |
| AlmaLinux 9 | mod_md | 1:2.4.26-2.el9_8.1 | ALSA-2026:30844 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 10 | mod_md | 1:2.4.26-5.el10_2.1 | RLSA-2026:30845 |
| Rocky Linux 9 | mod_md | 1:2.4.26-2.el9_8.1 | RLSA-2026:30844 |
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 | — |
| Azure Linux 3 | mod_md | No fix yet | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 10 | mod_md | 1:2.4.26-5.el10_2.1 | ELSA-2026-30845 |
| Oracle Linux 9 | mod_md | 1:2.4.26-2.el9_8.1 | ELSA-2026-30844 |
Advisories 24
- WID-SEC-2026-1354 Apache HTTP Server: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 11, 2026
- ALSA-2026:30844 Moderate: mod_md security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:30845 Moderate: mod_md security update AlmaLinux Security Advisories · Oct 29, 2026
- RHSA-2026:27200 Red Hat Security Advisory: Red Hat JBoss Core Services Apache HTTP Server 2.4.62 SP4 security update Red Hat Security Advisories (RHSA) · Oct 16, 2026
- RHSA-2026:57844 Red Hat Security Advisory: mod_md security update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- RHSA-2026:57641 Red Hat Security Advisory: mod_md security update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- RHSA-2026:57642 Red Hat Security Advisory: mod_md security update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- RHSA-2026:53537 Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- RHSA-2026:52393 Red Hat Security Advisory: mod_md security update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- RHSA-2026:30844 Red Hat Security Advisory: mod_md security update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- RHSA-2026:30845 Red Hat Security Advisory: mod_md security update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- SUSE-SU-2026:2641-1 Security update for apache2 SUSE / openSUSE Security Updates · Aug 27, 2026
- ELSA-2026-30845 Moderate: mod_md security update (Oracle Linux 10) Oracle Linux Security Advisories (ELSA) · Jul 16, 2026
- RLSA-2026:30845 Moderate: mod_md security update Rocky Linux Security Advisories · Jul 5, 2026
- RLSA-2026:30844 Moderate: mod_md security update Rocky Linux Security Advisories · Jul 1, 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
- ELSA-2026-30844 Moderate: mod_md security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Jun 29, 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