Advisory record · GHSA-6cqp-g7gg-8hr5

Netty: Security Control Bypass via CORS Short-Circuit Failure

CVSS 6.5 MediumEPSS 0.0041 · 35th percentile

Published by the GitHub Advisory Database at 22 Jul 2026, 21:42 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

PackageEcosystemAffectedFixed in
io.netty:netty-codec-httpMaven>=4.2.0.Final, <4.2.16.Final || <4.1.136.Final4.2.16.Final, 4.1.136.Final
Identifiers
GHSA-6cqp-g7gg-8hr5 · CVE-2026-56746
Weakness (CWE)
CWE-284
Published
22 Jul 2026
Updated
10 Sept 2026

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

Netty's netty-codec-http package, versions 4.2.0.Final before 4.2.16.Final and versions before 4.1.136.Final, has a flaw in its CORS handler where the shortCircuit() setting can be bypassed. An attacker who can send HTTP requests can send an Origin: null header to get unauthorized cross-origin requests forwarded to the backend application, bypassing access controls. Upgrade to 4.2.16.Final or 4.1.136.Final.

Written 2 Nov 2026.

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

ScoreRatingCVSSVectorSource
6.5 Medium 3.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N CNA (GitHub_M)
  • CISA KEV Not listed.
  • EPSS 0.0041, the 35th percentile, on 7 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

  1. 31 Oct 2026, 14:16 UTC First seen by agentprime
  2. 31 Oct 2026, 14:16 UTC Confirmed by OSV

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.