A AegiFlow
MEDIUMCVSS 6.3

CVE-2026-59898

CVE-2026-59898 updated by NVD

Published
2026-07-22
Modified
2026-07-31
Sources
github-advisory, nvd

Summary

Netty is an asynchronous, event-driven network application framework. Prior to versions 4.1.136.Final and 4.2.16.Final, ab attacker can force WebSocket upgrade via the lax V07 (or V08) handshaker by sending `Sec-WebSocket-Version: 7` and omitting `Connection: Upgrade` / `Upgrade: websocket` headers, completing a protocol switch that a proxy would not recognize as an Upgrade request and enabling HTTP request smuggling / protocol-confusion attacks. This issue has been fixed in versions 4.1.136.Final and 4.2.16.Final.

Affected packages

EcosystemPackageAffected versionsFixed versions
Mavenio.netty:netty-codec-http4.2.16.Final, 4.1.136.Final

Remediation: Upgrade to 4.2.16.Final or later.

References

Includes data from the GitHub Advisory Database, licensed under CC-BY 4.0.

Includes data from the National Vulnerability Database (NIST). NVD data is in the public domain; this page is not endorsed by NIST.

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