HIGH8.1
GHSA-3qp7-7mw8-wx86
Netty has an IPv6 Subnet Filter Bypass via Incorrect Comparator Masking
Quick fix
GHSA-3qp7-7mw8-wx86 — io.netty:netty-handler: upgrade to the fixed version with the command below.
# pom.xml: bump <version>4.2.15.Final</version> for io.netty:netty-handlerDetails
### 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.
Are you affected?
Enter the version of the package you're using.
Affected packages
Maven/io.netty:netty-handler
Introduced in:
4.2.0.FinalFixed in: 4.2.15.FinalFix
# pom.xml: bump <version>4.2.15.Final</version> for io.netty:netty-handlerMaven/io.netty:netty-handler
Introduced in:
0Fixed in: 4.1.135.FinalFix
# pom.xml: bump <version>4.1.135.Final</version> for io.netty:netty-handlerReferences
- https://github.com/netty/netty/security/advisories/GHSA-3qp7-7mw8-wx86[WEB]
- https://nvd.nist.gov/vuln/detail/CVE-2026-44249[ADVISORY]
- https://github.com/netty/netty[PACKAGE]
- https://github.com/netty/netty/releases/tag/netty-4.1.135.Final[WEB]
- https://github.com/netty/netty/releases/tag/netty-4.2.15.Final[WEB]