CVE-2026-27651

A flaw was found in NGINX, specifically within the ngx_mail_auth_http_module. When this module is enabled, and CRAM-MD5 or APOP authentication is active with an authentication server that permits retries, undisclosed requests can cause NGINX worker processes to terminate. This can lead to a Denial of Service (DoS), making the affected NGINX instance unavailable to legitimate users.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.