CVE-2026-27651

HIGH EPSS 40.9%
Published Mar 24, 20263mo ago · Modified Jun 17, 20262w ago
8.7 CVSS 4.0
High
Find Similar
Published Mar 24, 2026 3mo ago
Last Modified Jun 17, 2026 2w ago

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.

CVSS Details

Base Score
8.7
Exploitability
—
Impact
—
Vector string
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
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
40.9% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 1

CWE-476 NULL Pointer Dereference Memory Safety

Affected Products 14

VendorProductVersionRange
f5nginx_open_source*≥0.5.15  –  ≤0.9.7
f5nginx_open_source*≥1.0.0  –  <1.28.3
f5nginx_open_source*≥1.29.0  –  <1.29.7
f5nginx_plus*≥r33  –  <r35
f5nginx_plusr32any
f5nginx_plusr32any
f5nginx_plusr32any
f5nginx_plusr32any
f5nginx_plusr32any
f5nginx_plusr35any
f5nginx_plusr35any
f5nginx_plusr36any
f5nginx_plusr36any
f5nginx_plusr36any

References 1

  • my.f5.com https://my.f5.com/manage/s/article/K000160383
    Vendor Advisory

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.