Description
NGINX Plus and NGINX Open Source have a vulnerability in the ngx_mail_smtp_module module due to the improper handling of CRLF sequences in DNS responses. This allows an attacker-controlled DNS server to inject arbitrary headers into SMTP upstream requests, leading to potential request manipulation. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
Scores
CVSS v3
3.7
EPSS
0.0003
EPSS Percentile
6.8%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
partial
Details
CWE
CWE-93
Status
published
Products (13)
F5/NGINX Open Source
0.6.27 - 1.28.3
F5/NGINX Open Source
1.29.0 - 1.29.7
F5/NGINX Plus
R32 - R32 P5
F5/NGINX Plus
R33
F5/NGINX Plus
R34
F5/NGINX Plus
R35 - R35 P2
F5/NGINX Plus
R36 - R36 P3
f5/nginx_open_source
0.6.27 - 0.9.7
f5/nginx_plus
r32 p1 (4 CPE variants)
f5/nginx_plus
r33 (4 CPE variants)
... and 3 more
Published
Mar 24, 2026
Tracked Since
Mar 24, 2026