Description
Heap-based Buffer Overflow vulnerability in Apache HTTP Server with mod_xml2enc, xml2StartParse, and untrusted content
This issue affects Apache HTTP Server: from 2.4.0 through 2.4.67.
Users are recommended to upgrade to version 2.4.68, which fixes the issue.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Apache Software Foundation | Apache HTTP Server | 2.4.0 – ≤ 2.4.67 | — |
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 | 2.4.68-1 | — |
| Debian 13 | apache2 | 2.4.68-1~deb13u1 | — |
| Debian 12 | apache2 | 2.4.68-1~deb12u1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.04 LTS | apache2 | 2.4.66-2ubuntu2.4 | USN-8516-1 |
| Ubuntu 25.10 | apache2 | No fix yet | — |
| Ubuntu 24.04 LTS | apache2 | 2.4.58-1ubuntu8.15 | USN-8516-1 |
| Ubuntu 22.04 LTS | apache2 | 2.4.52-1ubuntu4.23 | USN-8516-1 |
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+esm5 | USN-8571-1 |
| Ubuntu Pro 18.04 LTS | apache2 | 2.4.29-1ubuntu4.27+esm10 | USN-8571-1 |
| Ubuntu Pro 16.04 LTS | apache2 | 2.4.18-2ubuntu3.17+esm19 | USN-8571-1 |
| Ubuntu Pro 14.04 LTS | apache2 | 2.4.7-1ubuntu4.22+esm14 | USN-8571-1 |
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 |
| RHEL 8 | httpd +6 | 2.4.37-65.module+el8.10.0+24521+219dcfc5.9 | RHSA-2026:42828 |
| RHEL 8 | mod_http2 | 1.15.7-10.module+el8.10.0+24521+219dcfc5.7 | RHSA-2026:42828 |
| RHEL 8 | mod_md | 1:2.0.8-8.module+el8.10.0+23815+1b5e1c66.2 | RHSA-2026:42828 |
| RHEL 8 | mod_ssl +1 | 1:2.4.37-65.module+el8.10.0+24521+219dcfc5.9 | RHSA-2026:42828 |
Show 6 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10.0 EUS | httpd +8 | 2.4.63-1.el10_0.4 | RHSA-2026:47046 |
| RHEL 10.0 EUS | mod_ssl +1 | 1:2.4.63-1.el10_0.4 | RHSA-2026:47046 |
| RHEL 9.6 EUS | httpd +8 | 2.4.62-4.el9_6.6 | RHSA-2026:62165 |
| RHEL 9.6 EUS | mod_ssl +1 | 1:2.4.62-4.el9_6.6 | RHSA-2026:62165 |
| RHEL 9.4 E4S | httpd +2 | 2.4.57-11.el9_4.5 | RHSA-2026:66323 |
| RHEL 9.4 E4S | mod_ssl +1 | 1:2.4.57-11.el9_4.5 | RHSA-2026:66323 |
| RHEL 9.2 E4S | httpd +2 | 2.4.53-11.el9_2.15 | RHSA-2026:67152 |
| RHEL 9.2 E4S | mod_ssl +1 | 1:2.4.53-11.el9_2.15 | RHSA-2026:67152 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-httpd +6 | 2.4.62-16.el8jbcs | RHSA-2026:56868 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-mod_http2 | 2.0.29-13.el8jbcs | RHSA-2026:56868 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-mod_ssl +1 | 1:2.4.62-16.el8jbcs | RHSA-2026:56868 |
| Red Hat Hardened Images 1 | httpd +5 | 2.4.68-1.hum1 | RHSA-2026:25042 |
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 +5 | 2.4.37-65.module_el8.10.0+4233+8b7d9181.9 | ALSA-2026:42828 |
| AlmaLinux 8 | mod_http2 | 1.15.7-10.module_el8.10.0+4233+8b7d9181.7 | ALSA-2026:42828 |
| AlmaLinux 8 | mod_md | 1:2.0.8-8.module_el8.10.0+4088+57f011c1.2 | ALSA-2026:42828 |
| AlmaLinux 8 | mod_ssl +1 | 1:2.4.37-65.module_el8.10.0+4233+8b7d9181.9 | ALSA-2026:42828 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 10 | httpd | 2.4.63-13.el10_2.4 | RLSA-2026:34109 |
| 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-2026:42828 |
| Rocky Linux 8 | mod_http2 | 1.15.7-10.module+el8.10.0+1775+6b057638 | RLSA-2026:42828 |
| Rocky Linux 8 | mod_md | 1:2.0.8-8.module+el8.9.0+1370+89cc8ad5 | RLSA-2026:42828 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | apache2 +6 | 2.4.66-150700.4.23.1 | SUSE-SU-2026:2759-1 |
| SLES 15 SP6 | apache2 +5 | 2.4.66-150600.5.55.1 | SUSE-SU-2026:2735-1 |
| 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 | 2.4.66-35.81.1 | SUSE-SU-2026:2717-1 |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | apache2 +6 | 2.4.66-160000.3.1 | SUSE-SU-2026:22564-1 |
| SLES for SAP 15 SP6 | apache2 +5 | 2.4.66-150600.5.55.1 | SUSE-SU-2026:2735-1 |
| 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 | 2.4.66-160000.3.1 | SUSE-SU-2026:22564-1 |
| 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 Leap 16.0 | apache2 +6 | 2.4.66-160000.3.1 | openSUSE-SU-2026:21235-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | apache2 | 2.4.68-r0 | — |
| Alpine v3.23 | apache2 | 2.4.68-r0 | — |
| Alpine v3.22 | apache2 | 2.4.68-r0 | — |
| Alpine v3.21 | apache2 | 2.4.68-r0 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | httpd +8 | 2.4.68-1.amzn2023.0.1 | ALAS2023-2026-1880 |
| Amazon Linux 2023 | mod_ssl +1 | 1:2.4.68-1.amzn2023.0.1 | ALAS2023-2026-1880 |
| Amazon Linux 2 | httpd +7 | 2.4.68-1.amzn2.0.1 | ALAS2-2026-3379 |
| Amazon Linux 2 | mod_ssl +1 | 1:2.4.68-1.amzn2.0.1 | ALAS2-2026-3379 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | httpd | 2.4.68-1 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 10 | httpd +8 | 2.4.63-13.0.1.el10_2.4 | ELSA-2026-34109 |
| Oracle Linux 10 | mod_ssl +1 | 1:2.4.63-13.0.1.el10_2.4 | ELSA-2026-34109 |
| 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+90969+a6381771.8 | ELSA-2026-42828 |
| Oracle Linux 8 | mod_http2 | 1.15.7-10.module+el8.10.0+90969+a6381771.7 | ELSA-2026-42828 |
| Oracle Linux 8 | mod_md | 1:2.0.8-8.module+el8.10.0+90899+db89cbcc.2 | ELSA-2026-42828 |
| Oracle Linux 8 | mod_ssl +1 | 1:2.4.37-65.0.1.module+el8.10.0+90969+a6381771.8 | ELSA-2026-42828 |
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
-
erberkan/CVE-2026-42536-PoC ★ 6 · Sep 13, 2026
Heap-based Buffer Overflow vulnerability in Apache HTTP Server with mod_xml2enc, xml2StartParse, and untrusted content
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 31
- WID-SEC-2026-2455 Oracle Solaris Drittanbieterkomponenten: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 12, 2026
- WID-SEC-2026-1824 Apache HTTP Server: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 11, 2026
- WID-SEC-2026-3595 IBM QRadar SIEM: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 2, 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
- ALSA-2026:42828 Important: httpd:2.4 security, bug fix, and enhancement update AlmaLinux Security Advisories · Oct 29, 2026
- RHSA-2026:56868 Red Hat Security Advisory: Red Hat JBoss Core Services Apache HTTP Server 2.4.62 SP5 security update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- RHSA-2026:67152 Red Hat Security Advisory: httpd security update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- RHSA-2026:66323 Red Hat Security Advisory: httpd security update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- RHSA-2026:62165 Red Hat Security Advisory: httpd security update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- RHSA-2026:47046 Red Hat Security Advisory: httpd security update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- RHSA-2026:42828 Red Hat Security Advisory: httpd:2.4 security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Oct 15, 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-2026:25042 Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- RLSA-2026:41906 Important: httpd security, bug fix, and enhancement update Rocky Linux Security Advisories · Jul 22, 2026
- ELSA-2026-42828 Important: httpd:2.4 security, bug fix, and enhancement update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Jul 22, 2026
- RLSA-2026:42828 Important: httpd:2.4 security, bug fix, and enhancement update Rocky Linux Security Advisories · Jul 21, 2026
- USN-8571-1 apache2 vulnerabilities Ubuntu Security Notices (USN) · Jul 21, 2026
- ELSA-2026-41906 Important: httpd security, bug fix, and enhancement update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Jul 20, 2026
- ELSA-2026-34109 Important: httpd security, bug fix, and enhancement update (Oracle Linux 10) Oracle Linux Security Advisories (ELSA) · Jul 16, 2026
- SUSE-SU-2026:22564-1 Security update for apache2 SUSE / openSUSE Security Updates · Jul 15, 2026
- openSUSE-SU-2026:21235-1 Security update for apache2 SUSE / openSUSE Security Updates · Jul 9, 2026
- USN-8516-1 apache2 vulnerabilities Ubuntu Security Notices (USN) · Jul 8, 2026
- RLSA-2026:34109 Important: httpd security, bug fix, and enhancement update Rocky Linux Security Advisories · Jul 7, 2026
- SUSE-SU-2026:2759-1 Security update for apache2 SUSE / openSUSE Security Updates · Jul 7, 2026
- SUSE-SU-2026:2735-1 Security update for apache2 SUSE / openSUSE Security Updates · Jul 4, 2026
- SUSE-SU-2026:2717-1 Security update for apache2 SUSE / openSUSE Security Updates · Jul 2, 2026
- SUSE-SU-2026:2686-1 Security update for apache2 SUSE / openSUSE Security Updates · Jul 1, 2026
- ALAS2-2026-3379 Moderate: httpd security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Jun 22, 2026
- ALAS2023-2026-1880 Moderate: httpd security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Jun 22, 2026
References
- https://httpd.apache.org/security/vulnerabilities_24.html vendor-advisory