Medium 6.5Published Jul 21, 2026

CVE-2026-56746Netty is a network application framework for development of protocol servers and clients.

Updated under an hour ago (2026-10-19 05:50 UTC)

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Exploited in the last 30 days

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.

CVSS: 6.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
Weakness (CWE): CWE-284
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Not given
NVD analysis: Analyzed
Record last updated: Jul 30, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

netty netty netty:netty	from 4.1.0 before 4.1.136; from 4.2.0 before 4.2.16	NVD

References

https://github.com/netty/netty/releases/tag/netty-4.1.136.Finalrelease-notes
https://github.com/netty/netty/releases/tag/netty-4.2.16.Finalrelease-notes
https://github.com/netty/netty/security/advisories/GHSA-6cqp-g7gg-8hr5vendor-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.