Incorrect Comparison in Netty - CVE-2026-44249
Published: June 8, 2026
Vulnerability identifier: #VU133457
CSH Severity: High
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber
CVE-ID: CVE-2026-44249
CWE-ID: CWE-697
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Netty project
Affected software:
Netty
Netty
Detailed vulnerability description
The vulnerability allows a remote attacker to bypass IPv6 subnet access controls.
The vulnerability exists due to incorrect comparison in IpSubnetFilterRule.compareTo() when evaluating IPv6 subnet rules. A remote attacker can use a valid public IP address to bypass IPv6 subnet access controls.
The issue is caused by applying a bitwise AND operation to the configured networkAddress instead of the subnetMask.
How to mitigate CVE-2026-44249
Install security update from vendor's website.