Vulnerability · Published Jun 8, 2026 · Assigned by apache
CVE-2026-34355Apache HTTP Server: mod_proxy_html 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 1.2% (higher than 67% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)7.5High
Exploit odds (30 days)1.2%top 32.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
A buffer overflow in mod_proxy_html in Apache HTTP Server 2.4.67 and earlier allows an attack by an untrusted backend. Users are recommended to upgrade to version 2.4.68, which fixes this 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-2026-34355 |
| Alpine:v3.22 | apache2 | 2.4.68-r0 | ALPINE-CVE-2026-34355 |
| Alpine:v3.23 | apache2 | 2.4.68-r0 | ALPINE-CVE-2026-34355 |
| Alpine:v3.24 | apache2 | 2.4.68-r0 | ALPINE-CVE-2026-34355 |
| Debian:12 | apache2 | 2.4.68-1~deb12u1 | DEBIAN-CVE-2026-34355 |
| Debian:13 | apache2 | 2.4.68-1~deb13u1 | DEBIAN-CVE-2026-34355 |
| Debian:14 | apache2 | 2.4.68-1 | DEBIAN-CVE-2026-34355 |
| 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-2026-34355 |
| Ubuntu:24.04:LTS | apache2 | 2.4.58-1ubuntu8.15 | UBUNTU-CVE-2026-34355 |
| Ubuntu:24.04:LTS | apache2 | 2.4.58-1ubuntu8.15 | USN-8516-1 |
| Ubuntu:25.10 | apache2 | no fix listed | UBUNTU-CVE-2026-34355 |
| 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-2026-34355 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Apache Software Foundation | Apache HTTP Server | 2.4.0 – through 2.4.67 |
Weakness: CWE-122, CWE-120 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References
- https://httpd.apache.org/security/vulnerabilities_24.html vendor-advisory
- http://www.openwall.com/lists/oss-security/2026/06/08/6
- https://access.redhat.com/security/cve/CVE-2026-34355 vdb-entry, x_refsource_REDHAT
- RHBZ#2486414 issue-tracking, x_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-34355.json x_sadp-csaf-vex
- https://access.redhat.com/errata/RHSA-2026:56868 vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:47046 vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:34109 vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:42828 vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:67152 vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:66323 vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:62165 vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:41906 vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:25042 vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:53371 vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:56869 vendor-advisory, x_refsource_REDHAT