cbcvebase.
CVE-2025-53859
published 2025-08-13

CVE-2025-53859: NGINX Open Source and NGINX Plus have a vulnerability in the ngx_mail_smtp_module that might allow an unauthenticated attacker to over-read NGINX SMTP…

medium6.3CVSS 4.0
AVNACLATPPRNUINVCLVINVANSCNSINSANEXCRXIRXARXMAVXMACXMATXMPRXMUIXMVCXMVIXMVAXMSCXMSIXMSAXSXAUXRXVXREXUX
NGINX Open Source and NGINX Plus have a vulnerability in the ngx_mail_smtp_module that might allow an unauthenticated attacker to over-read NGINX SMTP authentication process memory; as a result, the server side may leak arbitrary bytes sent in a request to the authentication server. This issue happens during the NGINX SMTP authentication process and requires the attacker to make preparations against the target system to extract the leaked data. The issue affects NGINX only if (1) it is built with the ngx_mail_smtp_module, (2) the smtp_auth directive is configured with method "none," and (3) the authentication server returns the "Auth-Wait" response header. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Affected

26 ranges· showing 25
VendorProductVersion rangeFixed in
debiannginx< nginx 1.22.1-9+deb12u3 (bookworm)nginx 1.22.1-9+deb12u3 (bookworm)
f5nginx>= 0 < 1.28.2-r01.28.2-r0
f5nginx>= 0 < 1.28.2-r01.28.2-r0
f5nginx>= 0 < 1.22.1-9+deb12u31.22.1-9+deb12u3
f5nginx>= 0 < 1.26.3-3+deb13u11.26.3-3+deb13u1
f5nginx>= 0 < 1.28.0-31.28.0-3
f5nginx_open_source
f5nginx_open_source>= 0.7 < 1.29.11.29.1
f5nginx_open_source>= 0.7.22 < 1.29.11.29.1
f5nginx_plus
f5nginx_plus
f5nginx_plus
f5nginx_plus
f5nginx_plus
f5nginx_plus
f5nginx_plus>= R30 < **
f5nginx_plus>= R31 < **
f5nginx_plus>= R32 < R32 P3R32 P3
f5nginx_plus>= R33 < R33 P3R33 P3
f5nginx_plus>= R34 < R34 P2R34 P2
msrcazl3_gh_2.62.0-1_on_azure_linux_3.0
msrcazl3_gh_2.62.0-8_on_azure_linux_3.0
msrcazl3_nginx_1.25.4-4_on_azure_linux_3.0
msrcazl3_nginx_1.25.4-5_on_azure_linux_3.0
msrccbl2_nginx_1.22.1-13_on_cbl_mariner_2.0

CVSS provenance

nvdv4.06.3MEDIUMCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/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
osv6.3MEDIUM