CVE-2026-27651
HIGH7.5EPSS 0.06%NGINX ngx_mail_auth_http_module vulnerability
Published: 3/24/2026Modified: 3/26/2026
Also known as:ALPINE-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.
Affected packages (4)
- Alpine/nginxfrom 0, < 1.28.3-r0
- Bitnami/nginx>= 0.5.15, < 1.28.3, >= 1.29.0, < 1.29.7
- Bitnami/nginx-gateway>= 0.5.15, < 1.28.3, >= 1.29.0, < 1.29.7
- Debian/nginxfrom 0, < 1.18.0-6.1+deb11u6
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | 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 |
| osv | CVSS 3.1 | HIGH7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |