CVE-2026-27651

CVE Details

Release Date:	2026-03-24
Impact:	Important	What is this?

Description

When the ngx_mail_auth_http_module module is enabled on NGINX Plus or NGINX Open Source, undisclosed requests can cause worker processes to terminate. This issue may occur when (1) CRAM-MD5 or APOP authentication is enabled, and (2) the authentication server permits retry by returning the Auth-Wait response header. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

See more information about CVE-2026-27651 from MITRE CVE dictionary and NIST NVD

NOTE: The following CVSS metrics and score provided are preliminary and subject to review.

CVSS v3 metrics

Base Score:	7.5
Vector String:	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Version:	3.1
Attack Vector:	Network
Attack Complexity:	Low
Privileges Required:	None
User Interaction:	None
Scope:	Unchanged
Confidentiality Impact:	None
Integrity Impact:	None
Availability Impact:	High

Errata information

Platform	Errata	Release Date
Oracle Linux version 10 (nginx)	ELSA-2026-6906	2026-04-07
Oracle Linux version 8 (nginx)	ELSA-2026-6907	2026-04-08
Oracle Linux version 9 (nginx)	ELSA-2026-6923	2026-04-08
Oracle Linux version 9 (nginx)	ELSA-2026-7002	2026-04-08