CVE-2026-28753
published 2026-03-24CVE-2026-28753: 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…
medium6.3CVSS 4.0
AVNACHATPPRNUINVCNVILVANSCNSINSANEXCRXIRXARXMAVXMACXMATXMPRXMUIXMVCXMVIXMVAXMSCXMSIXMSAXSXAUXRXVXREXUX
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
20 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | nginx | < nginx 1.28.3-1 (forky) | nginx 1.28.3-1 (forky) |
| f5 | nginx | >= 0 < 1.28.3-1 | 1.28.3-1 |
| f5 | nginx_open_source | — | — |
| f5 | nginx_open_source | >= 0.6.27 < 1.28.3 | 1.28.3 |
| f5 | nginx_open_source | 0.6.27 – 0.9.7 | — |
| f5 | nginx_open_source | >= 1.0.0 < 1.28.3 | 1.28.3 |
| f5 | nginx_open_source | >= 1.29.0 < 1.29.7 | 1.29.7 |
| f5 | nginx_plus | — | — |
| f5 | nginx_plus | — | — |
| f5 | nginx_plus | — | — |
| f5 | nginx_plus | — | — |
| f5 | nginx_plus | — | — |
| f5 | nginx_plus | — | — |
| f5 | nginx_plus | >= R32 < R32 P5 | R32 P5 |
| f5 | nginx_plus | >= R33 < * | * |
| f5 | nginx_plus | >= R34 < * | * |
| f5 | nginx_plus | >= R35 < R35 P2 | R35 P2 |
| f5 | nginx_plus | >= R36 < R36 P3 | R36 P3 |
| msrc | azl3_nginx_1.28.2-1_on_azure_linux_3.0 | — | — |
| msrc | cbl2_nginx_1.22.1-15_on_cbl_mariner_2.0 | — | — |
CVSS provenance
nvdv4.06.3MEDIUMCVSS: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
osv6.3MEDIUM