CRLF Injection Affecting netty package, versions <1:4.1.48-9ubuntu0.1+esm3


Severity

Recommended
medium

Based on Ubuntu security rating.

Threat Intelligence

EPSS
0.2% (10th percentile)

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  • Snyk IDSNYK-UBUNTU2404-NETTY-16781233
  • published3 Jun 2026
  • disclosed13 May 2026

Introduced: 13 May 2026

CVE-2026-42586  (opens in a new tab)
CWE-93  (opens in a new tab)

How to fix?

Upgrade Ubuntu:24.04 netty to version 1:4.1.48-9ubuntu0.1+esm3 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream netty package and not the netty package as distributed by Ubuntu. See How to fix? for Ubuntu:24.04 relevant fixed versions and status.

Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, the Netty Redis codec encoder (RedisEncoder) writes user-controlled string content directly to the network output buffer without validating or sanitizing CRLF (\r\n) characters. Since the Redis Serialization Protocol (RESP) uses CRLF as the command/response delimiter, an attacker who can control the content of a Redis message can inject arbitrary Redis commands or forge fake responses. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.

CVSS Base Scores

version 3.1