---
id: CVE-2026-73636
title: >-
  Authentication bypass by capture-replay in mod_auth_digest in Apache Software
  Foundation Apache HTTP Server 2.4.x on all platforms allows a
  man-in-the-middle (MITM) attacker to replay captured digest authentication
  credentials via crafte…
summary: >-
  Authentication bypass by capture-replay in mod_auth_digest in Apache Software
  Foundation Apache HTTP Server 2.4.x on all platforms allows a
  man-in-the-middle (MITM) attacker to replay captured digest authentication
  credentials via crafte…
severity: high
cvss: 8.1
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-294
vendor: apache
product: http_server
affected:
  - 'http_server >= 2.4.0, < 2.4.69'
patched:
  - http_server 2.4.69
published: '2026-10-01'
updated: '2026-10-05'
sourceUpdated: '2026-10-05T17:45:24.813'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-73636'
references:
  - url: 'https://httpd.apache.org/security/vulnerabilities_24.html'
    label: security@apache.org
  - url: 'http://www.openwall.com/lists/oss-security/2026/10/01/27'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-73636.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-73636'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2544849'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-73636'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-73636'
  - url: 'https://access.redhat.com/errata/RHSA-2026:74858'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00397
epssPercentile: 0.33764
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-01T19:43:35.472082Z'
ingestedAt: '2026-10-01T18:55:42.365Z'
---

## Overview

Authentication bypass by capture-replay in mod_auth_digest in Apache Software Foundation Apache HTTP Server 2.4.x on all platforms allows a man-in-the-middle (MITM) attacker to replay captured digest authentication credentials via crafted requests that trigger garbage collection of the client's shared memory entry when AuthDigestNonceLifetime is set to 0.

Users are recommended to upgrade to version 2.4.69, which fixes this issue.

## Affected

- `http_server >= 2.4.0, < 2.4.69`

## Remediation

Upgrade past the affected range:

- `http_server 2.4.69`

## Vendor advisories

- **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat Hardened Images · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, … · updated 2026-10-02 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-73636.json)
- **RHSA-2026:74858** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-10-02 · [advisory](https://access.redhat.com/errata/RHSA-2026:74858)