CVE-2026-42586

Netty: CRLF Injection in Netty Redis Codec Encoder

State: Published
Severity: 6.8 Medium
Published: May 13, 2026
Updated: May 14, 2026
Reserved: Apr 28, 2026

Description

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.

Scores

CVSS	Score	Vector	Source
3.1	6.8 Medium	CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N	GitHub_M

Weaknesses

CWE-93 Improper Neutralization of CRLF Sequences ('CRLF Injection')

Affected Products

Product	Versions
nettynetty	>= 4.2.0.Alpha1, < 4.2.13.FinalAffected < 4.1.133.FinalAffected
netty-codec-redisio.netty	>= 4.2.0.Alpha1, < 4.2.13.FinalAffected < 4.1.133.FinalAffected

References

https://github.com/netty/netty/security/advisories/GHSA-rgrr-p7gp-5xj7

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