CVE-2026-42586Public exploit

Redis command injection via unvalidated CRLF content

Published May 13, 2026 · Updated May 13, 2026

CRLF injection in Netty's Redis codec before 4.1.133.Final or 4.2.0.Alpha1 through 4.2.12.Final allows attackers to inject Redis commands. RedisEncoder.writeString writes text message content with ByteBufUtil.writeUtf8 without rejecting embedded carriage returns or line feeds before appending RESP's CRLF delimiter. Exploitation requires unsanitized attacker-controlled content in an inline command, simple-string, or error message; length-prefixed array and bulk-string messages are unaffected.

CVSS severity6.8
Medium
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

CRLF injection in Netty's Redis codec before 4.1.133.Final or 4.2.0.Alpha1 through 4.2.12.Final allows attackers to inject Redis commands. RedisEncoder.writeString writes text message content with ByteBufUtil.writeUtf8 without rejecting embedded carriage returns or line feeds before appending RESP's CRLF delimiter. Exploitation requires unsanitized attacker-controlled content in an inline command, simple-string, or error message; length-prefixed array and bulk-string messages are unaffected.

The record

CVE
CVE-2026-42586
Published
May 13, 2026
Updated
May 13, 2026
Vendor
The Netty Project
Product
netty-codec-redis
Classifications
CWE-93
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 13, 2026CVE publishedPublication date reported by the CVE source.
  2. May 13, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 4.1.133.Final
  2. Affected versionversion=>= 4.2.0.Alpha1, < 4.2.13.Final

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

The Netty Project · netty-codec-redisversion=< 4.1.133.Final; version=>= 4.2.0.Alpha1, < 4.2.13.Final
The Netty Project · Nettyversion=< 4.1.133.Final; version=>= 4.2.0.Alpha1, < 4.2.13.Final

Published CVSS scores

6.8GitHub, Inc.CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N
7.1NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

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

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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