CVE-2026-56746 Security Details

CVE ID

CVE-2026-56746

CWE

CWE-284

CVE Description

Netty is a network application framework for development of protocol servers and clients. Versions 4.2.0.Final through 4.2.15.Final and 4.1.0.Final through 4.1.135.Final, are vulnerable to security control bypass during the origin evaluation process. CorsHandler provides a shortCircuit() configuration designed to reject unauthorized cross-origin requests immediately, acting as a security control before requests reach the application. However, due to a logical operator error in the origin evaluation process, this protection can be entirely bypassed. An attacker can bypass the short-circuit mechanism by sending a request with an Origin: null header. This failure forwards unauthorized requests to the backend application, bypassing intended access controls. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.

Published

Jul 21, 2026

CVSS Score & Severity

6.5Medium

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

EPSS Score

0.379%

Malware

malware

KEV Status

Not in KEV Catalog: No known exploits

Affected Ecosystems

affected

Source

National Vulnerability Database

References

GitHub · netty/nettyPROJECT