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Fencer Intel
high 8.1

CVE-2026-73636 json

Apache HTTP Server: mod_auth_digest one-time-nonce replay attack

published last mo. modified last mo. also BIT-apache-2026-73636 , EUVD-2026-90907

cvss
8.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 34%
public exploits
0
none known

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 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.

Patch / fix

  • bitnami apache 2.4.69
  • apache http_server 2.4.69
  • apache2 Debian 13 2.4.69-1~deb13u1
  • apache2 Debian 14 2.4.69-1

debian advisories DEBIAN-CVE-2026-73636

  • apache2 Ubuntu 22.04 LTS 2.4.52-1ubuntu4.25
  • apache2 Ubuntu 24.04 LTS 2.4.58-1ubuntu8.17
  • apache2 Ubuntu 26.04 LTS 2.4.66-2ubuntu2.6
  • apache2 Ubuntu Pro 14.04 LTS 2.4.7-1ubuntu4.22+esm17
  • apache2 Ubuntu Pro 16.04 LTS 2.4.18-2ubuntu3.17+esm22
  • apache2 Ubuntu Pro 18.04 LTS 2.4.29-1ubuntu4.27+esm13
  • apache2 Ubuntu Pro 20.04 LTS 2.4.41-4ubuntu3.23+esm9

ubuntu advisories UBUNTU-CVE-2026-73636

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • httpd hummingbird 1 2.4.69-1.hum1
  • mod_lua hummingbird 1 2.4.69-1.hum1
  • mod_ssl hummingbird 1 2.4.69-1.hum1
  • mod_ldap hummingbird 1 2.4.69-1.hum1
  • httpd-core hummingbird 1 2.4.69-1.hum1
  • httpd-tools hummingbird 1 2.4.69-1.hum1
  • mod_session hummingbird 1 2.4.69-1.hum1
  • httpd-manual hummingbird 1 2.4.69-1.hum1

red hat advisories RHSA-2026:74858

  • apache2 SLE Module for Basesystem 15 SP7 2.4.66-150700.4.26.1
  • apache2-event SLE Module for Package Hub 15 SP7 2.4.66-150700.4.26.1
  • apache2-utils SLE Module for Server Applications 15 SP7 2.4.66-150700.4.26.1
  • apache2-manual SLE Module for Server Applications 15 SP7 2.4.66-150700.4.26.1
  • apache2-worker SLE Module for Server Applications 15 SP7 2.4.66-150700.4.26.1
  • apache2-prefork SLE Module for Basesystem 15 SP7 2.4.66-150700.4.26.1
  • apache2 SLES for SAP 15 SP5, SLES for SAP 15 SP4, SLES 15 SP5-LTSS +5 more 2.4.66-150400.6.60.1
  • apache2 SLES LTSS Extended Security 12 SP5, SLES 12 SP5-LTSS 2.4.66-35.84.1

suse advisories SUSE-SU-2026:5099-1SUSE-SU-2026:5077-1SUSE-SU-2026:5076-1SUSE-SU-2026:5075-1

  • httpd AlmaLinux 8 2.4.37-65.module_el8.10.0+4332+2bef2e0d.13
  • mod_md AlmaLinux 8 1:2.0.8-8.module_el8.10.0+4295+280de5aa.4
  • mod_ssl AlmaLinux 8 1:2.4.37-65.module_el8.10.0+4332+2bef2e0d.13
  • mod_ldap AlmaLinux 8 2.4.37-65.module_el8.10.0+4332+2bef2e0d.13
  • mod_http2 AlmaLinux 8 1.15.7-10.module_el8.10.0+4233+8b7d9181.7
  • mod_http2 AlmaLinux 8 1.15.7-10.module_el8.10.0+4270+e5f13fdb.7
  • httpd-tools AlmaLinux 8 2.4.37-65.module_el8.10.0+4332+2bef2e0d.13
  • mod_session AlmaLinux 8 2.4.37-65.module_el8.10.0+4332+2bef2e0d.13

almalinux advisories ALSA-2026:92616ALSA-2026:89860ALSA-2026:88229

  • httpd Rocky Linux 8 2.4.37-65.module+el8.10.0+40197+0231e209.8
  • httpd Rocky Linux 8 2.4.37-65.module+el8.10.0+1842+4a9649e8.2
  • httpd Rocky Linux 8 2.4.37-65.module+el8.10.0+1938+3b7755d4.3
  • httpd Rocky Linux 8 2.4.37-65.module+el8.10.0+40206+be2c8a50.8
  • httpd Rocky Linux 8 2.4.37-65.module+el8.10.0+40257+286895ef.9
  • httpd Rocky Linux 8 2.4.37-65.module+el8.10.0+1984+1bed3124.4
  • httpd Rocky Linux 8 2.4.37-65.module+el8.10.0+40312+2c72bb9b.10
  • httpd Rocky Linux 8 2.4.37-65.module+el8.10.0+2061+8d03fdec.5

rocky linux advisories RLSA-2026:92616RLSA-2026:89860RLSA-2026:88229

  • apache2 Alpine 3.24, Alpine 3.23, Alpine 3.22 +1 more 2.4.69-r0

alpine advisories ALPINE-CVE-2026-73636

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • httpd Azure Linux 3.0 2.4.69-1

azure linux advisories AZL-106758

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Is CVE-2026-73636 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-73636 updated cvss 8.1

httpd: httpd: Authentication bypass via credential replay in mod_auth_digest

  • Red Hat Enterprise Linux 7 httpd, mod_ssl, mod_ldap, httpd-tools, mod_session, httpd-manual, +1 more Red Hat JBoss Core Services jbcs-httpd24-httpd, jbcs-httpd24-mod_md, jbcs-httpd24-mod_ssl, jbcs-httpd24-mod_ldap, jbcs-httpd24-httpd-zip, jbcs-httpd24-httpd-libs, +6 more
    affected: workaround, no fix available
  • Red Hat Enterprise Linux AppStream (v. 8) mod_md 2.0.8-8.module+el8.10.0+24941+3af7c60a.4, httpd 2.4.37-65.module+el8.10.0+25092+6f3ea0dd.13, mod_ssl 2.4.37-65.module+el8.10.0+25092+6f3ea0dd.13, mod_http2 1.15.7-10.module+el8.10.0+24521+219dcfc5.7, mod_ldap 2.4.37-65.module+el8.10.0+25092+6f3ea0dd.13, httpd-tools 2.4.37-65.module+el8.10.0+25092+6f3ea0dd.13, +4 more
    fixed: vendor fix RHSA-2026:92616
  • Red Hat Enterprise Linux AppStream (v. 9) httpd 2.4.62-13.el9_8.9, mod_lua 2.4.62-13.el9_8.9, mod_ssl 2.4.62-13.el9_8.9, mod_ldap 2.4.62-13.el9_8.9, httpd-core 2.4.62-13.el9_8.9, httpd-tools 2.4.62-13.el9_8.9, +4 more
    fixed: vendor fix RHSA-2026:88229
  • Red Hat Enterprise Linux AppStream (v. 10) httpd 2.4.63-13.el10_2.8, mod_lua 2.4.63-13.el10_2.8, mod_ssl 2.4.63-13.el10_2.8, mod_ldap 2.4.63-13.el10_2.8, httpd-core 2.4.63-13.el10_2.8, httpd-tools 2.4.63-13.el10_2.8, +4 more
    fixed: vendor fix RHSA-2026:89860
  • Red Hat Hardened Images httpd 2.4.69-1.hum1, mod_lua 2.4.69-1.hum1, mod_ssl 2.4.69-1.hum1, mod_ldap 2.4.69-1.hum1, httpd-core 2.4.69-1.hum1, httpd-tools 2.4.69-1.hum1, +4 more
    fixed: vendor fix RHSA-2026:74858
  • Red Hat Enterprise Linux 6 httpd, mod_ssl, httpd-tools, httpd-manual
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
last mo.

Exploit prediction

0.40% chance of exploitation in the next 30 days, higher than 34% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CISA ADP 3.1 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA 3.1 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
OSV 3.1 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
bitnami apache
>=2.4.0, <2.4.69
2.4.69

Affected products

  • Apache Software Foundation Apache HTTP Server

Classification

Weakness
  • CWE-294 Authentication Bypass by Capture-replay
Technology feeds

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.