CVE-2026-44892

Netty has a Vulnerable Default Configuration Which Leads to Denial of Service via Unbounded HTTP/3 Header Size

State: Published
Severity: 7.5 High
Published: Jun 12, 2026
Updated: Jun 12, 2026
Reserved: May 7, 2026

Description

Netty is a network application framework for development of protocol servers and clients. Prior to version 4.2.15.Final, the default configuration of the `Http3ConnectionHandler` in the Netty HTTP/3 codec lacks an enforced maximum header size limit. When a peer does not explicitly specify `HTTP3_SETTINGS_MAX_FIELD_SECTION_SIZE`, the implementation defaults to an unbounded limit. This insecure default configuration allows a malicious client or server to send an enormous number of headers, leading to a memory exhaustion Denial of Service via an `OutOfMemoryError`. Version 4.2.15.Final contains a patch.

Scores

CVSS	Score	Vector	Source
3.1	7.5 High	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H	GitHub_M

Weaknesses

CWE-400 Uncontrolled Resource Consumption
CWE-1188 Insecure Default Initialization of Resource

Affected Products

Product	Versions
nettynetty	>= 4.2.0.Final, < 4.2.15.FinalAffected

References

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