What’s Vulnerable › Vulnerabilities

CVE-2026-73637: Apache HTTP Server: mod_auth_digest DoS attack

• Severity: high (CVSS 7.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-01 · updated 2026-10-05
• Weakness: CWE-416

Description

Use after free in mod_auth_digest in Apache Software Foundation Apache HTTP Server before 2.4.69 on all platforms allows an unauthenticated remote client to cause authentication state corruption via concurrent Digest authentication requests when AuthDigestNcCheck is enabled or AuthDigestNonceLifetime is set to 0. Users are recommended to upgrade to version 2.4.69, which fixes this issue.

Affected products

• Apache HTTP Server: from 2.4.0 before 2.4.69 — fixed in 2.4.69

How to fix

Upgrade to a fixed version: Apache HTTP Server 2.4.69. Check the vendor advisory for mitigations.

References

• https://httpd.apache.org/security/vulnerabilities_24.html
• http://www.openwall.com/lists/oss-security/2026/10/01/28

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