cbcvebase.
CVE-2026-27651
published 2026-03-24

CVE-2026-27651: 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…

high8.7CVSS 4.0
AVNACLATNPRNUINVCNVINVAHSCNSINSANEXCRXIRXARXMAVXMACXMATXMPRXMUIXMVCXMVIXMVAXMSCXMSIXMSAXSXAUXRXVXREXUX
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

19 ranges
VendorProductVersion rangeFixed in
debiannginx< nginx 1.28.3-1 (forky)nginx 1.28.3-1 (forky)
f5nginx>= 0 < 1.28.3-11.28.3-1
f5nginx_open_source
f5nginx_open_source>= 0.5.15 < 1.28.31.28.3
f5nginx_open_source0.5.15 – 0.9.7
f5nginx_open_source>= 1.0.0 < 1.28.31.28.3
f5nginx_open_source>= 1.29.0 < 1.29.71.29.7
f5nginx_plus
f5nginx_plus
f5nginx_plus
f5nginx_plus
f5nginx_plus>= R32 < R32 P5R32 P5
f5nginx_plus>= R33 < **
f5nginx_plus>= R34 < **
f5nginx_plus>= R35 < R35 P2R35 P2
f5nginx_plus>= R36 < R36 P3R36 P3
f5nginx_plus>= r33 < r35r35
msrcazl3_nginx_1.28.2-1_on_azure_linux_3.0
msrccbl2_nginx_1.22.1-15_on_cbl_mariner_2.0

CVSS provenance

nvdv4.08.7HIGHCVSS: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
osv8.7HIGH