Riskcovery

CVE-2026-42584

Netty: HttpClientCodec response desynchronization

State
Published
Severity
7.3 High
Published
May 13, 2026
Updated
Sep 18, 2026
Reserved
Apr 28, 2026

Read the record on cve.org

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.

Scores

CVSSScoreVectorSource
3.17.3 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:LGitHub_M
3.17.3 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:Lredhat-SADP

Weaknesses

  • CWE-444 Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

Affected Products

ProductVersions
nettynetty
  • >= 4.2.0.Alpha1, < 4.2.13.FinalAffected
  • < 4.1.133.FinalAffected
netty-codec-httpio.netty
  • >= 4.2.0.Alpha1, < 4.2.13.FinalAffected
  • < 4.1.133.FinalAffected

References

Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.