Netty has an IPv6 Subnet Filter Bypass via Incorrect Comparator Masking
### 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.
describes (1)
Related CVEs.
| ID | severity | exploitable | ||
|---|---|---|---|---|
| CVE-2026-44249US | — | — | ||
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… | ||||
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