CVE-2026-28753
NGINX ngx_mail_proxy_module vulnerability
MEDIUM 6.3
At a glance
- Source
- NVD
- EPSS
- EPSS 0.27 % · percentile 20 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- f5
- NVD status
- Analyzed
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.
Weaknesses (CWE)
- CWE-93 — Improper Neutralization of CRLF Sequences
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | LOW 3.7 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N | f5 |
| CVSS 4.0 | MEDIUM 6.3 | 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 | f5 |
| CVSS 4.0 | MEDIUM 6.3 | 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 | NVD · f5sirt@f5.com (Secondary) |
| CVSS 3.1 | LOW 3.7 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N | NVD · f5sirt@f5.com (Secondary) |
European references
- ENISA EUVD · EUVD-2026-14885
- GCVE · GCVE-0-2026-28753
CERT-FR advisories
- CERTFR-2026-AVI-1056 — Multiples vulnérabilités dans les produits Splunk · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0376 — Multiples vulnérabilités dans les produits Microsoft · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0352 — Multiples vulnérabilités dans les produits F5 · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:a:f5:nginx_plus:r32:p1:*:*:*:*:*:*cpe:2.3:a:f5:nginx_plus:r32:p2:*:*:*:*:*:*cpe:2.3:a:f5:nginx_plus:r32:p3:*:*:*:*:*:*cpe:2.3:a:f5:nginx_plus:r32:p4:*:*:*:*:*:*cpe:2.3:a:f5:nginx_plus:r33:*:*:*:*:*:*:*cpe:2.3:a:f5:nginx_plus:r33:p1:*:*:*:*:*:*cpe:2.3:a:f5:nginx_plus:r33:p2:*:*:*:*:*:*cpe:2.3:a:f5:nginx_plus:r33:p3:*:*:*:*:*:*cpe:2.3:a:f5:nginx_plus:r34:*:*:*:*:*:*:*cpe:2.3:a:f5:nginx_plus:r34:p1:*:*:*:*:*:*cpe:2.3:a:f5:nginx_plus:r34:p2:*:*:*:*:*:*cpe:2.3:a:f5:nginx_plus:r35:*:*:*:*:*:*:*cpe:2.3:a:f5:nginx_plus:r35:p1:*:*:*:*:*:*cpe:2.3:a:f5:nginx_plus:r36:*:*:*:*:*:*:*cpe:2.3:a:f5:nginx_plus:r36:p1:*:*:*:*:*:*cpe:2.3:a:f5:nginx_plus:r36:p2:*:*:*:*:*:*cpe:2.3:a:f5:nginx_open_source:*:*:*:*:*:*:*:*≥ 0.6.27 ≤ 0.9.7cpe:2.3:a:f5:nginx_open_source:*:*:*:*:*:*:*:*≥ 1.0.0 < 1.28.3cpe:2.3:a:f5:nginx_open_source:*:*:*:*:*:*:*:*≥ 1.29.0 < 1.29.7
Affected products
| Product | Versions |
|---|---|
| F5 · NGINX Open Source | affected 1.29.0 < 1.29.7 ; affected 0.6.27 < 1.28.3 |
| F5 · NGINX Plus | affected R36 < R36 P3 ; affected R35 < R35 P2 ; affected R34 < * ; affected R33 < * ; affected R32 < R32 P5 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |