Vulnerability · Published Jun 8, 2026 · Assigned by apache
CVE-2026-34356Apache HTTP Server: ProxyPassReverseCookieMap buffer overflow
High 7.5
In plain English
A high-severity heap buffer overflow in Apache HTTP Server from Apache Software Foundation. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 54% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)7.5High
Exploit odds (30 days)0.7%top 46.3% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Heap-based Buffer Overflow vulnerability in Apache HTTP Server with malicious backend servers and ProxyPassReverseCookie* 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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:10 | httpd | 2.4.63-13.el10_2.4 | ALSA-2026:34109 |
| AlmaLinux:8 | httpd | 2.4.37-65.module_el8.10.0+4233+8b7d9181.9 | ALSA-2026:42828 |
| AlmaLinux:9 | httpd | 2.4.62-13.el9_8.5 | ALSA-2026:41906 |
| AlmaLinux:10 | httpd-core | 2.4.63-13.el10_2.4 | ALSA-2026:34109 |
| AlmaLinux:9 | httpd-core | 2.4.62-13.el9_8.5 | ALSA-2026:41906 |
| AlmaLinux:10 | httpd-devel | 2.4.63-13.el10_2.4 | ALSA-2026:34109 |
| AlmaLinux:8 | httpd-devel | 2.4.37-65.module_el8.10.0+4233+8b7d9181.9 | ALSA-2026:42828 |
| AlmaLinux:9 | httpd-devel | 2.4.62-13.el9_8.5 | ALSA-2026:41906 |
| AlmaLinux:10 | httpd-filesystem | 2.4.63-13.el10_2.4 | ALSA-2026:34109 |
| AlmaLinux:9 | httpd-filesystem | 2.4.62-13.el9_8.5 | ALSA-2026:41906 |
| AlmaLinux:10 | httpd-manual | 2.4.63-13.el10_2.4 | ALSA-2026:34109 |
| AlmaLinux:8 | httpd-manual | 2.4.37-65.module_el8.10.0+4233+8b7d9181.9 | ALSA-2026:42828 |
| AlmaLinux:9 | httpd-manual | 2.4.62-13.el9_8.5 | ALSA-2026:41906 |
| AlmaLinux:10 | httpd-tools | 2.4.63-13.el10_2.4 | ALSA-2026:34109 |
| AlmaLinux:8 | httpd-tools | 2.4.37-65.module_el8.10.0+4233+8b7d9181.9 | ALSA-2026:42828 |
| AlmaLinux:9 | httpd-tools | 2.4.62-13.el9_8.5 | ALSA-2026:41906 |
| AlmaLinux:8 | mod_http2 | 1.15.7-10.module_el8.10.0+4233+8b7d9181.7 | ALSA-2026:42828 |
| AlmaLinux:10 | mod_ldap | 2.4.63-13.el10_2.4 | ALSA-2026:34109 |
| AlmaLinux:8 | mod_ldap | 2.4.37-65.module_el8.10.0+4233+8b7d9181.9 | ALSA-2026:42828 |
| AlmaLinux:9 | mod_ldap | 2.4.62-13.el9_8.5 | ALSA-2026:41906 |
| AlmaLinux:10 | mod_lua | 2.4.63-13.el10_2.4 | ALSA-2026:34109 |
| AlmaLinux:9 | mod_lua | 2.4.62-13.el9_8.5 | ALSA-2026:41906 |
| AlmaLinux:8 | mod_md | 1:2.0.8-8.module_el8.10.0+4088+57f011c1.2 | ALSA-2026:42828 |
| AlmaLinux:10 | mod_proxy_html | 1:2.4.63-13.el10_2.4 | ALSA-2026:34109 |
| AlmaLinux:8 | mod_proxy_html | 1:2.4.37-65.module_el8.10.0+4233+8b7d9181.9 | ALSA-2026:42828 |
| AlmaLinux:9 | mod_proxy_html | 1:2.4.62-13.el9_8.5 | ALSA-2026:41906 |
| AlmaLinux:10 | mod_session | 2.4.63-13.el10_2.4 | ALSA-2026:34109 |
| AlmaLinux:8 | mod_session | 2.4.37-65.module_el8.10.0+4233+8b7d9181.9 | ALSA-2026:42828 |
| AlmaLinux:9 | mod_session | 2.4.62-13.el9_8.5 | ALSA-2026:41906 |
| AlmaLinux:10 | mod_ssl | 1:2.4.63-13.el10_2.4 | ALSA-2026:34109 |
| AlmaLinux:8 | mod_ssl | 1:2.4.37-65.module_el8.10.0+4233+8b7d9181.9 | ALSA-2026:42828 |
| AlmaLinux:9 | mod_ssl | 1:2.4.62-13.el9_8.5 | ALSA-2026:41906 |
| Alpine:v3.21 | apache2 | 2.4.68-r0 | ALPINE-CVE-2026-34356 |
| Alpine:v3.22 | apache2 | 2.4.68-r0 | ALPINE-CVE-2026-34356 |
| Alpine:v3.23 | apache2 | 2.4.68-r0 | ALPINE-CVE-2026-34356 |
| Alpine:v3.24 | apache2 | 2.4.68-r0 | ALPINE-CVE-2026-34356 |
| Debian:12 | apache2 | 2.4.68-1~deb12u1 | DEBIAN-CVE-2026-34356 |
| Debian:13 | apache2 | 2.4.68-1~deb13u1 | DEBIAN-CVE-2026-34356 |
| Debian:14 | apache2 | 2.4.68-1 | DEBIAN-CVE-2026-34356 |
| Rocky Linux:10 | httpd | 0:2.4.63-13.el10_2.4 | RLSA-2026:34109 |
| Rocky Linux:8 | httpd | 0:2.4.37-65.module+el8.10.0+2061+8d03fdec.5 | RLSA-2026:42828 |
| Rocky Linux:8 | httpd | 0:2.4.37-65.module+el8.10.0+1984+1bed3124.4 | RLSA-2026:42828 |
| Rocky Linux:8 | httpd | 0:2.4.37-65.module+el8.10.0+1938+3b7755d4.3 | RLSA-2026:42828 |
| Rocky Linux:8 | httpd | 0:2.4.37-65.module+el8.10.0+40045+6ce8579b.6 | RLSA-2026:42828 |
| Rocky Linux:8 | httpd | 0:2.4.37-65.module+el8.10.0+40206+be2c8a50.8 | RLSA-2026:42828 |
| Rocky Linux:8 | httpd | 0:2.4.37-65.module+el8.10.0+40053+5a18018e.7 | RLSA-2026:42828 |
| Rocky Linux:8 | httpd | 0:2.4.37-65.module+el8.10.0+1830+22f0c9e0 | RLSA-2026:42828 |
| Rocky Linux:8 | httpd | 0:2.4.37-65.module+el8.10.0+1842+4a9649e8.2 | RLSA-2026:42828 |
| Rocky Linux:8 | httpd | 0:2.4.37-65.module+el8.10.0+1840+b070a976.1 | RLSA-2026:42828 |
| Rocky Linux:8 | httpd | 0:2.4.37-65.module+el8.10.0+40197+0231e209.8 | RLSA-2026:42828 |
| Rocky Linux:9 | httpd | 0:2.4.62-13.el9_8.5 | RLSA-2026:41906 |
| Rocky Linux:8 | mod_http2 | 0:1.15.7-10.module+el8.10.0+2061+8d03fdec.4 | RLSA-2026:42828 |
| Rocky Linux:8 | mod_http2 | 0:1.15.7-10.module+el8.10.0+1883+38ed6c58.1 | RLSA-2026:42828 |
| Rocky Linux:8 | mod_http2 | 0:1.15.7-10.module+el8.10.0+40197+0231e209.5 | RLSA-2026:42828 |
| Rocky Linux:8 | mod_http2 | 0:1.15.7-10.module+el8.10.0+1830+22f0c9e0 | RLSA-2026:42828 |
| Rocky Linux:8 | mod_http2 | 0:1.15.7-10.module+el8.10.0+1938+3b7755d4.3 | RLSA-2026:42828 |
| Rocky Linux:8 | mod_http2 | 0:1.15.7-10.module+el8.10.0+1775+6b057638 | RLSA-2026:42828 |
| Rocky Linux:8 | mod_http2 | 0:1.15.7-10.module+el8.10.0+40204+716978aa.6 | RLSA-2026:42828 |
| Rocky Linux:8 | mod_md | 1:2.0.8-8.module+el8.9.0+1370+89cc8ad5 | RLSA-2026:42828 |
| Rocky Linux:8 | mod_md | 1:2.0.8-8.module+el8.10.0+40053+5a18018e.2 | RLSA-2026:42828 |
| Ubuntu:22.04:LTS | apache2 | 2.4.52-1ubuntu4.23 | USN-8516-1 |
| Ubuntu:22.04:LTS | apache2 | 2.4.52-1ubuntu4.23 | UBUNTU-CVE-2026-34356 |
| Ubuntu:24.04:LTS | apache2 | 2.4.58-1ubuntu8.15 | UBUNTU-CVE-2026-34356 |
| Ubuntu:24.04:LTS | apache2 | 2.4.58-1ubuntu8.15 | USN-8516-1 |
| Ubuntu:25.10 | apache2 | no fix listed | UBUNTU-CVE-2026-34356 |
| Ubuntu:26.04:LTS | apache2 | 2.4.66-2ubuntu2.4 | USN-8516-1 |
| Ubuntu:26.04:LTS | apache2 | 2.4.66-2ubuntu2.4 | UBUNTU-CVE-2026-34356 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Apache Software Foundation | Apache HTTP Server | 2.4.0 – through 2.4.67 |
Weakness: CWE-122 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H