Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, HttpClientCodec pairs each inbound response with an outbound request by queue.poll() once per response, including for 1xx. If the client pipelines GET then HEAD and the server sends 103, then 200 with GET body, then 200 for HEAD, the queue pairs HEAD with the first 200. The HEAD rule then skips reading that message’s body, so the GET entity bytes stay on the stream and the following 200 is parsed from the wrong offset. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.
History

Mon, 18 May 2026 12:15:00 +0000

Type Values Removed Values Added
CPEs cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*

Fri, 15 May 2026 08:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 14 May 2026 15:00:00 +0000

Type Values Removed Values Added
First Time appeared Io.netty
Io.netty netty-codec-http
Netty
Netty netty
Vendors & Products Io.netty
Io.netty netty-codec-http
Netty
Netty netty

Wed, 13 May 2026 18:30:00 +0000

Type Values Removed Values Added
Description Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, HttpClientCodec pairs each inbound response with an outbound request by queue.poll() once per response, including for 1xx. If the client pipelines GET then HEAD and the server sends 103, then 200 with GET body, then 200 for HEAD, the queue pairs HEAD with the first 200. The HEAD rule then skips reading that message’s body, so the GET entity bytes stay on the stream and the following 200 is parsed from the wrong offset. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.
Title Netty: HttpClientCodec response desynchronization
Weaknesses CWE-444
References
Metrics cvssV3_1

{'score': 7.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-05-13T18:10:48.437Z

Updated: 2026-05-13T18:35:05.734Z

Reserved: 2026-04-28T17:26:12.086Z

Link: CVE-2026-42584

cve-icon Vulnrichment

Updated: 2026-05-13T18:34:51.803Z

cve-icon NVD

Status : Analyzed

Published: 2026-05-13T19:17:24.043

Modified: 2026-05-18T12:15:02.740

Link: CVE-2026-42584

cve-icon Redhat

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