CVE-2026-44249 PUBLISHED

Netty has an IPv6 Subnet Filter Bypass via Incorrect Comparator Masking

Assigner: GitHub_M
Reserved: 05.05.2026 Published: 11.06.2026 Updated: 11.06.2026

Netty is a network application framework for development of protocol servers and clients. In netty-handler prior to versions 4.1.135.Final and 4.2.15.Final, an attacker can bypass IPv6 subnet rules due to an incorrect masking operation in IpSubnetFilterRule.compareTo(). Valid public IP addresses can bypass the restrictions. Versions 4.1.135.Final and 4.2.15.Final patch the issue.

Metrics

CVSS 3.1

CVSS Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS Score: 8.1

Attack Vector	Network	Scope	Unchanged
Attack Complexity	High	Confidentiality Impact	High
Privileges Required	None	Integrity Impact	High
User Interaction	None	Availability Impact	High

CVSS 3.1

Product Status

Vendor	netty
Product	netty
Versions	Version >= 4.2.0.Final, < 4.2.15.Final is affected Version < 4.1.135.Final is affected

References

Problem Types

CWE-284: Improper Access Control CWE
CWE-697: Incorrect Comparison CWE