CVE-2026-27651

Published: Mar 24, 2026Modified: Jul 15, 2026

8.7

Vector

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

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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:XShow less

Source: f5sirt@f5.com (Secondary)

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.

Affected (14)

Products: F5: Nginx Open Source, Nginx Plus

2 products

Nginx Open Source

Configuration A

14 vulnerable

Vulnerable Software	Affected Versions
F5 Nginx Open Source	From 0.5.15 to 0.9.7
F5 Nginx Open Source	From 1.0.0 to 1.28.3
F5 Nginx Open Source	From 1.29.0 to 1.29.7
F5 Nginx Plus	From r33 to r35
F5 Nginx Plus	Version r32
F5 Nginx Plus	Version r32 p1
F5 Nginx Plus	Version r32 p2
F5 Nginx Plus	Version r32 p3
F5 Nginx Plus	Version r32 p4
F5 Nginx Plus	Version r35
F5 Nginx Plus	Version r35 p1
F5 Nginx Plus	Version r36
F5 Nginx Plus	Version r36 p1
F5 Nginx Plus	Version r36 p2

Related CWEs

NULL Pointer Dereference

The product dereferences a pointer that it expects to be valid but is NULL.

References (19)

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

Source: f5sirt@f5.com

Vendor Advisory

https://access.redhat.com/errata/RHSA-2026:10065

Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

https://access.redhat.com/errata/RHSA-2026:13634

Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

https://access.redhat.com/errata/RHSA-2026:13680

Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

https://access.redhat.com/errata/RHSA-2026:13839

Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

https://access.redhat.com/errata/RHSA-2026:14836

Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

https://access.redhat.com/errata/RHSA-2026:15942

Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

https://access.redhat.com/errata/RHSA-2026:15943

Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

https://access.redhat.com/errata/RHSA-2026:15945

Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

https://access.redhat.com/errata/RHSA-2026:15966

Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

https://access.redhat.com/errata/RHSA-2026:6906

Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

https://access.redhat.com/errata/RHSA-2026:6907

Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

https://access.redhat.com/errata/RHSA-2026:6923

Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

https://access.redhat.com/errata/RHSA-2026:7002

Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

https://access.redhat.com/errata/RHSA-2026:7343

Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

https://access.redhat.com/errata/RHSA-2026:8346

Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

https://access.redhat.com/security/cve/CVE-2026-27651

Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

https://bugzilla.redhat.com/show_bug.cgi?id=2450791

Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-27651.json

Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

Timeline

No history available yet.