SecuriTricks - CVE-2026-27651

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.

Product(s) Impacted

Vendor	Product	Versions
Nginx	Nginx Plus Nginx Open Source	* *

Weaknesses

Common security weaknesses mapped to this vulnerability.

CWE-476

NULL Pointer Dereference

A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit.

*CPE(s)

Affected systems and software identified for this CVE.

Type	Vendor	Product	Version	Update	Edition	Language	Software Edition	Target Software	Target Hardware	Other Information
a	nginx	nginx_plus	/	/	/	/	/	/	/	/
a	nginx	nginx_open_source	/	/	/	/	/	/	/	/

References

https://my.f5.com/manage/s/article/K000160383

CVSS Score

8.7 / 10

CVSS Data - 4.0

Attack Vector: NETWORK
Attack Complexity: LOW
Attack Requirements: NONE
Privileges Required: NONE
User Interaction: NONE
Scope:
Confidentiality Impact: NONE
Integrity Impact: NONE
Availability Impact: HIGH
Exploit Maturity: NOT_DEFINED

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

View Vector String

Timeline

Published: March 24, 2026, 3:16 p.m.
Last Modified: March 24, 2026, 3:53 p.m.

Status : Awaiting Analysis

CVE has been marked for Analysis. Normally once in this state the CVE will be analyzed by NVD staff within 24 hours.

More info

Source

[email protected]

CVE-2026-27651