GitHub Advisoryadvisory · Maven

GHSA-3qp7-7mw8-wx86 Netty has an IPv6 Subnet Filter Bypass via Incorrect Comparator Masking

HIGH Published 2026-06-08 Modified 2026-06-12 Official page ↗
Aliases
CVE-2026-44249
Ecosystem
Maven
Packages
io.netty:netty-handler
Severity
High
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Weaknesses
CWE-284, CWE-697
Reviewed
2026-06-08

Affected packages

• Maven io.netty:netty-handler: >= 4.2.0.Final, < 4.2.15.Final → fixed in 4.2.15.Final • Maven io.netty:netty-handler: < 4.1.135.Final → fixed in 4.1.135.Final

Description

Summary An attacker can bypass IPv6 subnet rules due to an incorrect masking operation in IpSubnetFilterRule.compareTo(). Valid public IP addresses can bypass the restrictions. Details `io.netty.handler.ipfilter.IpSubnetFilterRule#compareTo(java.net.InetSocketAddress)` method performs a bitwise AND between the incoming IP address and the configured networkAddress, instead of the subnetMask. Impact Access Control Bypass. Attacker can bypass IpSubnetFilter IPv6 access controls.

Related

Alias · CVE (1)

  • CVE-2026-44249 Netty is a network application framework for development of protocol servers and clients. vulnerability

Weakness · CWE (2)

  • CWE-284 Improper Access Control weakness
  • CWE-697 Incorrect Comparison weakness

References