CVE-2026-44892 HIGH

CVE-2026-44892: Netty has a Vulnerable Default Configuration Which Leads to Denial of Service via Unbounded HTTP/3 Header Size

Vendor Netty
Product netty
Weakness CWE-400
Published June 12, 2026
Last update June 12, 2026

CVSS base score

7.5/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality None
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

June 12, 2026 CVE published
June 12, 2026 Record updated