CVE-2026-73636 Apache HTTP Server: mod_auth_digest one-time-nonce replay attack

What is CVE-2026-73636?

CVE-2026-73636 is a high-severity authentication bypass vulnerability in Apache Http Server, published on 1 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

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.

Weakness: CWE-294

Which versions are affected by CVE-2026-73636?

1 open source package ship an affected version, including apache. It affects 1 product.

Products include Apache Http Server.

How do I fix CVE-2026-73636?

Upgrade apache to 2.4.69 or later.

Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.

Is CVE-2026-73636 being exploited?

There is no known exploitation of CVE-2026-73636 in the wild and no public exploit code.

Other vulnerabilities in Apache Http Server

• CVE-2021-42013 Apache HTTP Server Path Traversal Exploited Critical 9.8
• CVE-2024-38475 Apache HTTP Server Improper Escaping of Output Exploited Critical 9.1
• CVE-2021-40438 Apache HTTP Server-Side Request Forgery (SSRF) Exploited Critical 9.0
• CVE-2019-0211 Apache HTTP Server Privilege Escalation Exploited High 7.8
• CVE-2021-41773 Apache HTTP Server Path Traversal Exploited High 7.5

All Apache Http Server vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as ALPINE-CVE-2026-73636, AZL-106758, BELL-CVE-2026-73636, BIT-apache-2026-73636, DEBIAN-CVE-2026-73636, ECHO-e525-7fd8-e0a9 and 4 more.