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

7.5HIGH

Key Information:

Vendor

Netty

Status
Netty
Vendor
CVE Published:
12 June 2026

What is CVE-2026-44892?

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.

Affected Version(s)

netty >= 4.2.0.Final, < 4.2.15.Final

References

https://github.com/netty/netty/security/advisories/GHSA-c...
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https://github.com/netty/netty/releases/tag/netty-4.2.15....
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CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.