What’s Vulnerable › Vulnerabilities

CVE-2026-34355: Apache HTTP Server: mod_proxy_html buffer overflow

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-06-08 · updated 2026-09-14
• Weakness: CWE-122

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 products

• Apache HTTP Server: from 2.4.0 before 2.4.68 — fixed in 2.4.68

How to fix

Upgrade to a fixed version: Apache HTTP Server 2.4.68. Check the vendor advisory for mitigations.

References

• https://httpd.apache.org/security/vulnerabilities_24.html
• http://www.openwall.com/lists/oss-security/2026/06/08/6
• https://access.redhat.com/errata/RHSA-2026:25042
• https://access.redhat.com/errata/RHSA-2026:34109
• https://access.redhat.com/errata/RHSA-2026:41906
• https://access.redhat.com/errata/RHSA-2026:42828
• https://access.redhat.com/errata/RHSA-2026:47046
• https://access.redhat.com/errata/RHSA-2026:53371
• https://access.redhat.com/errata/RHSA-2026:56868
• https://access.redhat.com/errata/RHSA-2026:56869
• https://access.redhat.com/errata/RHSA-2026:62165
• https://access.redhat.com/errata/RHSA-2026:66323

Get alerted when CVE-2026-34355 or the next vulnerability affects your stack