CRLF Injection Affecting nginx package, versions <1.28.3-r0


Severity

Recommended
0.0
low
0
10

Snyk's Security Team recommends NVD's CVSS assessment. Learn more

Threat Intelligence

EPSS
0.26% (18th percentile)

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  • Snyk IDSNYK-ALPINE324-NGINX-17297413
  • published11 Jun 2026
  • disclosed24 Mar 2026

Introduced: 24 Mar 2026

CVE-2026-28753  (opens in a new tab)
CWE-93  (opens in a new tab)

How to fix?

Upgrade Alpine:3.24 nginx to version 1.28.3-r0 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream nginx package and not the nginx package as distributed by Alpine. See How to fix? for Alpine:3.24 relevant fixed versions and status.

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 Base Scores

version 3.1