CVE-2026-28753
Published:March 24, 2026
Updated:April 23, 2026
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.
Affected Packages
https://github.com/nginx/nginx.git (GITHUB):
Affected version(s) >=release-0.1.0 <release-1.28.3Fix Suggestion:
Update to version release-1.28.3https://github.com/nginx/nginx.git (GITHUB):
Affected version(s) >=release-1.29.0 <release-1.29.7Fix Suggestion:
Update to version release-1.29.7Related Resources (1)
Do you need more information?
Contact UsCVSS v4
Base Score:
6.3
Attack Vector
NETWORK
Attack Complexity
HIGH
Attack Requirements
PRESENT
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
LOW
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
3.7
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
LOW
Availability
NONE
Weakness Type (CWE)
Improper Neutralization of CRLF Sequences ('CRLF Injection')
EPSS
Base Score:
0.02
