High severity · published Oct 1, 2026
CVE-2026-73637
Apache HTTP Server: mod_auth_digest DoS attack
7.3
CVSS
0.5%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
Low
Availability
Low
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 40% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
HS
HTTP Server · Apache
2.4.0 through 2.4.68 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-73637
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-73637
vendor-advisory
https://httpd.apache.org/security/vulnerabilities_24.html
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