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.
CVSS Metrics
- Vector
- CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/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
- Attack Vector
- network
- Complexity
- high
- Privileges
- none
- User Action
- none
- Confidentiality
- undefined
- Integrity
- undefined
- Availability
- undefined
- Weaknesses
- CWE-93
Metadata
- Primary Vendor
- F5
- Published
- 3/24/2026
- Last Modified
- 3/26/2026
- Source
- NIST NVD
- Note: Verify all details with official vendor sources before applying patches.
Affected Products
f5 : nginx_plusf5 : nginx_plusf5 : nginx_plusf5 : nginx_plusf5 : nginx_plusf5 : nginx_plusf5 : nginx_plusf5 : nginx_plusf5 : nginx_plusf5 : nginx_plusf5 : nginx_plusf5 : nginx_plusf5 : nginx_plusf5 : nginx_plusf5 : nginx_plusf5 : nginx_plusf5 : nginx_open_sourcef5 : nginx_open_sourcef5 : nginx_open_source
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