CRLF Injection Affecting nginx-source package, versions <1.21.5-150400.3.15.1


Severity

Recommended
0.0
low
0
10

Based on SUSE Linux Enterprise Server security rating.

Threat Intelligence

EPSS
0.26% (18th percentile)

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  • Snyk IDSNYK-SLES155-NGINXSOURCE-16756663
  • published19 May 2026
  • disclosed18 May 2026

Introduced: 18 May 2026

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

How to fix?

Upgrade SLES:15.5 nginx-source to version 1.21.5-150400.3.15.1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream nginx-source package and not the nginx-source package as distributed by SLES. See How to fix? for SLES:15.5 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