CRLF Injection Affecting netty package, versions *


Severity

Recommended
0.0
high
0
10

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Threat Intelligence

EPSS
0.27% (20th percentile)

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  • Snyk IDSNYK-ECHOLATEST-NETTY-19946219
  • published19 Sept 2026
  • disclosed18 Sept 2026

Introduced: 18 Sep 2026

NewCVE-2026-93576  (opens in a new tab)
CWE-93  (opens in a new tab)

How to fix?

There is no fixed version for Echo:latest netty.

NVD Description

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

A flaw was found in Netty netty-codec-smtp. The component does not properly validate Carriage Return (CR) and Line Feed (LF) characters in the SMTP command-name field. A remote attacker, if an application routes untrusted input into this field, can embed CR/LF characters to inject arbitrary SMTP commands. This can lead to SMTP command smuggling, allowing for unauthorized email relay or spoofing of sender/recipient addresses. While the impact is significant, the real-world exploitability is considered lower as applications typically do not place user-controlled data in the command-name field.

CVSS Base Scores

version 3.1