Cyber Resilience

CVE-2026-73636

Auth Bypass in Apache Http Server 2.4.0 – 2.4.69

Auth Bypass
Published
01 October 2026
Modified
05 October 2026
Patch / advisory
View advisory
CVSS Score v3.1 8.1
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0041 33th percentile
Risk Priority 59 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2026-73636 is a high-severity Authentication Bypass by Capture-replay (CWE-294) vulnerability in Apache Http Server. Its CVSS base score is 8.1 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Remote Services (T1021); ranked at the 33th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SC-23 (Session Authenticity) and SC-8 (Transmission Confidentiality and Integrity) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A07:2025 Authentication Failures

EU & UK References

Vulnerability Data

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…

more

entry when AuthDigestNonceLifetime is set to 0. Users are recommended to upgrade to version 2.4.69, which fixes this issue.

CWE(s)
CWE-294

Related Threats

MITRE ATT&CK Enterprise Techniques

T1021 Remote Services Lateral Movement
Adversaries may use [Valid Accounts](https://attack.
attack.mitre.org →
T1021.002 SMB/Windows Admin Shares Lateral Movement
Adversaries may use [Valid Accounts](https://attack.
attack.mitre.org →
T1040 Network Sniffing Credential Access
Adversaries may passively sniff network traffic to capture information about an environment, including authentication material passed over the network.
attack.mitre.org →
T1114.002 Remote Email Collection Collection
Adversaries may target an Exchange server, Office 365, or Google Workspace to collect sensitive information.
attack.mitre.org →
T1133 External Remote Services Persistence
Adversaries may leverage external-facing remote services to initially access and/or persist within a network.
attack.mitre.org →
T1550.004 Web Session Cookie Lateral Movement
Adversaries can use stolen session cookies to authenticate to web applications and services.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-58098Same product: Apache Http Server
CVE-2026-48005Same product: Apache Http Server
CVE-2023-25690Same product: Apache Http Server
CVE-2026-44631Same product: Apache Http Server
CVE-2026-34059Same product: Apache Http Server
CVE-2026-63686Same product: Apache Http Server
CVE-2025-66200Same product: Apache Http Server
CVE-2026-47360Same product: Apache Http Server
CVE-2026-59685Same product: Apache Http Server
CVE-2026-42536Same product: Apache Http Server

Affected Assets

apache
http server
2.4.0 — 2.4.69

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V10.4.16
  • V10.5.1

Mitigating Controls (NIST 800-53 r5) AI

SC-23 Session Authenticity partial match

Session authenticity mechanisms directly stop replay of captured authentication traffic by enforcing freshness or cryptographic binding.

SC-8 Transmission Confidentiality and Integrity partial match

Transmission integrity (with anti-replay) stops captured messages from being accepted as valid later.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

DE.CM-01 partial match
blocks

Network monitoring may detect anomalous replays after the fact but does not prevent the design flaw.

PR.AA-03 partial match
blocks

Strong authentication methods can reduce replay risk but do not inherently address captured messages.

PR.AA-04 partial match
blocks

Protecting and verifying identity assertions prevents replay of captured authentication material.

PR.DS-02 partial match
blocks

Encryption and integrity protections for data-in-transit directly block capture-replay of credentials or tokens.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.5.14 Information transfer partial match
removes
A.5.15 Access control partial match
removes
A.5.16 Identity management partial match
removes
A.5.17 Authentication information partial match
removes
A.5.18 Access rights partial match
removes
A.8.10 Information deletion partial match
removes

References