---
id: CVE-2026-34355
title: >-
  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.
summary: >-
  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.
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-122
  - CWE-120
vendor: apache
product: http_server
affected:
  - 'http_server >= 2.4.0, < 2.4.68'
patched:
  - http_server 2.4.68
published: '2026-06-08'
updated: '2026-09-14'
sourceUpdated: '2026-09-14T13:18:18.583'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-34355'
references:
  - url: 'https://httpd.apache.org/security/vulnerabilities_24.html'
    label: security@apache.org
  - url: 'http://www.openwall.com/lists/oss-security/2026/06/08/6'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://access.redhat.com/errata/RHSA-2026:25042'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:34109'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:41906'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:42828'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:47046'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:53371'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:56868'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:56869'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:62165'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:66323'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:67152'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/security/cve/CVE-2026-34355'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2486414'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-34355.json
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-34355'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-34355'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-06-08T18:11:57.581951Z'
epss: 0.01161
epssPercentile: 0.6583
ingestedAt: '2026-07-16T12:53:56.287Z'
---

## Overview

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

- `http_server >= 2.4.0, < 2.4.68`

## Remediation

Upgrade past the affected range:

- `http_server 2.4.68`

## Vendor advisories

- **RHSA-2026:56868** · Red Hat · fixed in: Red Hat JBoss Core Services on RHEL 8 · released 2026-08-19 · [advisory](https://access.redhat.com/errata/RHSA-2026:56868)
- **RHSA-2026:47046** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v. 10.0) · released 2026-07-28 · [advisory](https://access.redhat.com/errata/RHSA-2026:47046)
- **RHSA-2026:34109** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10) · released 2026-07-01 · [advisory](https://access.redhat.com/errata/RHSA-2026:34109)
- **RHSA-2026:42828** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 8) · released 2026-07-21 · [advisory](https://access.redhat.com/errata/RHSA-2026:42828)
- **RHSA-2026:66323** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.9.4) · released 2026-09-10 · [advisory](https://access.redhat.com/errata/RHSA-2026:66323)
- **RHSA-2026:62165** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v.9.6) · released 2026-09-01 · [advisory](https://access.redhat.com/errata/RHSA-2026:62165)
- **RHSA-2026:41906** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9) · released 2026-07-20 · [advisory](https://access.redhat.com/errata/RHSA-2026:41906)
- **RHSA-2026:25042** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-06-10 · [advisory](https://access.redhat.com/errata/RHSA-2026:25042)
- **RHSA-2026:53371** · Red Hat · fixed in: Red Hat Insights proxy 1.5 · released 2026-08-11 · [advisory](https://access.redhat.com/errata/RHSA-2026:53371)
- **RHSA-2026:56869** · Red Hat · fixed in: Red Hat JBoss Core Services 2.4.62.SP5 · released 2026-08-19 · [advisory](https://access.redhat.com/errata/RHSA-2026:56869)
- **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7 · updated 2026-09-18 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-34355.json)
- **RHSA-2026:67152** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.9.2) · released 2026-09-14 · [advisory](https://access.redhat.com/errata/RHSA-2026:67152)
