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High severityNVD Advisory· Published Mar 27, 2026· Updated Mar 31, 2026

Netty HTTP/2 CONTINUATION Frame Flood DoS via Zero-Byte Frame Bypass

CVE-2026-33871

Description

Netty is an asynchronous, event-driven network application framework. In versions prior to 4.1.132.Final and 4.2.10.Final, a remote user can trigger a Denial of Service (DoS) against a Netty HTTP/2 server by sending a flood of CONTINUATION frames. The server's lack of a limit on the number of CONTINUATION frames, combined with a bypass of existing size-based mitigations using zero-byte frames, allows an user to cause excessive CPU consumption with minimal bandwidth, rendering the server unresponsive. Versions 4.1.132.Final and 4.2.10.Final fix the issue.

AI Insight

LLM-synthesized narrative grounded in this CVE's description and references.

Affected packages

Versions sourced from the GitHub Security Advisory.

PackageAffected versionsPatched versions
io.netty:netty-codec-http2Maven
< 4.1.132.Final4.1.132.Final
io.netty:netty-codec-http2Maven
>= 4.2.0.Alpha1, < 4.2.11.Final4.2.11.Final

Affected products

208

Patches

Vulnerability mechanics

References

3

News mentions

1