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… (CVE-2026-42586)
Description
Netty versions prior to 4.2.13.Final and 4.1.133.Final contain a vulnerability in the RedisEncoder component where user-controlled string content is written directly to the network output buffer without sanitizing CRLF characters. This allows an attacker controlling Redis message content to inject arbitrary Redis commands or forge responses. The issue is fixed in versions 4.2.13.Final and 4.1.133.Final.
CVSS v3.1
Score 7.1high
Affected software
pkg:deb/ubuntu/netty?arch=source&distro=esm-apps/bionicpkg:deb/ubuntu/netty?arch=source&distro=esm-apps/focalpkg:deb/ubuntu/netty?arch=source&distro=esm-apps/jammypkg:deb/ubuntu/netty?arch=source&distro=esm-apps/noblepkg:deb/ubuntu/netty?arch=source&distro=questingpkg:deb/ubuntu/netty?arch=source&distro=stonkingpkg:deb/ubuntu/netty?arch=source&distro=esm-apps/resoluteRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Netty Redis codec encoder (RedisEncoder) in versions before 4.2.13.Final and 4.1.133.Final improperly handles user-controlled string content by writing it directly to the network output buffer without validating or sanitizing CRLF (\r\n) characters. Since the Redis Serialization Protocol (RESP) uses CRLF as a delimiter for commands and responses, this flaw enables an attacker who controls Redis message content to inject arbitrary Redis commands or forge fake responses. This vulnerability has a CVSS 3.1 score of 7.1 (medium severity) and is addressed by patches in versions 4.2.13.Final and 4.1.133.Final.
Potential Impact
An attacker able to control the content of Redis messages can exploit this vulnerability to inject arbitrary Redis commands or forge responses, potentially leading to unauthorized command execution or manipulation of Redis communication. This can compromise the integrity and reliability of Redis operations using the affected Netty Redis codec encoder.
Mitigation Recommendations
A fix is available and has been released in Netty versions 4.2.13.Final and 4.1.133.Final. Users should upgrade to these or later versions to remediate the vulnerability. Refer to the official Ubuntu security notice USN-8401-1 for patch details and application instructions.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- UBUNTU-CVE-2026-42586
- Osv Schema Version
- 1.7.0
- Ecosystems
- ["Ubuntu:Pro:18.04:LTS","Ubuntu:Pro:20.04:LTS","Ubuntu:Pro:22.04:LTS","Ubuntu:Pro:24.04:LTS","Ubuntu:25.10","Ubuntu:26.10","Ubuntu:Pro:26.04:LTS"]
- Cvss Version
- 3.1
Patch Information
Threat ID: 6ad3f6812cdf04f6566671e1
Added to database: 10/17/2026, 22:28:17 UTC
Last enriched: 10/18/2026, 01:39:24 UTC
Last updated: 10/18/2026, 01:39:24 UTC
Views: 8
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