CVE-2026-42586 PUBLISHED

Netty: CRLF Injection in Netty Redis Codec Encoder

Assigner: GitHub_M
Reserved: 28.04.2026 Published: 13.05.2026 Updated: 13.05.2026

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.

Metrics

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

Product Status

Vendor netty
Product netty
Versions
  • Version >= 4.2.0.Alpha1, < 4.2.13.Final is affected
  • Version < 4.1.133.Final is affected
Vendor io.netty
Product netty-codec-redis
Versions
  • Version >= 4.2.0.Alpha1, < 4.2.13.Final is affected
  • Version < 4.1.133.Final is affected

References

Problem Types

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