MEDIUM

CVE-2026-56746

CVSS v3

6.5

MEDIUM

EPSS Score

0.4 %

exploit probability, as of 2026-10-19

CISA KEV

known exploited

Exploitation

—

SSVC status

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Affected and fixed versions

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

io.netty:netty-codec-httpMavenall versions · fixed in 4.1.136.Final

Vendor advisories

CVE-2026-56746 Red Hat Product Security484 products fixed · 35 known affected
io.netty/netty-codec-http: Netty: Security control bypass allows unauthorized requests via null origin header
openshift-serverless-1/kn-ekb-dispatcher-rhel9 as a component of OpenShift Serverless · openshift-serverless-1/kn-ekb-receiver-rhel9 as a component of OpenShift Serverless · openshift-serverless-1/kn-eventing-integrations-aws-ddb-streams-source-rhel9 as a component of OpenShift Serverless
RHSA-2026:84734 Red Hat Product Security9 products fixed
Red Hat Security Advisory: RHOAI 3.4.5 - Red Hat OpenShift AI
RHSA-2026:76637 Red Hat Product Security1 product fixed
Red Hat Security Advisory: Apicurio Registry (container images) release and security update [ 3.3.3 GA ]
RHSA-2026:70277 Red Hat Product Security1 product fixed
Red Hat Security Advisory: Red Hat JBoss Enterprise Application Platform 8.1.8 security update
RHSA-2026:70230 Red Hat Product Security147 products fixed
Red Hat Security Advisory: Red Hat JBoss Enterprise Application Platform 8.1.8 security update
RHSA-2026:70228 Red Hat Product Security148 products fixed
Red Hat Security Advisory: Red Hat JBoss Enterprise Application Platform 8.1.8 security update

13 more advisories

Full record on NVD

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.

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
Published: 2026-07-21
Last Modified: 2026-07-22
GitHub Advisory: GHSA-6cqp-g7gg-8hr5

Frequently asked questions

What is CVE-2026-56746?

Is CVE-2026-56746 actively exploited?

Active exploitation of CVE-2026-56746 has not been confirmed. Its EPSS score was 0.4% on 2026-10-19, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-56746?

CVE-2026-56746 has a CVSS v3 base score of 6.5 (MEDIUM severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N.

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