CVE-2026-27651
March 24, 2026
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.
Affected Packages
https://github.com/nginx/nginx.git (GITHUB):
Affected version(s) >=release-0.1.0 <release-1.28.3Fix Suggestion:
Update to version release-1.28.3https://github.com/nginx/nginx.git (GITHUB):
Affected version(s) >=release-0.1.0 <release-1.28.3Fix Suggestion:
Update to version release-1.28.3https://github.com/nginx/nginx.git (GITHUB):
Affected version(s) >=release-0.1.0 <release-1.28.3Fix Suggestion:
Update to version release-1.28.3Related Resources (1)
Do you need more information?
Contact UsCVSS v4
Base Score:
8.7
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.5
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Weakness Type (CWE)
NULL Pointer Dereference
EPSS
Base Score:
0.03
