---
id: CVE-2026-93573
title: A flaw was found in Netty's HTTP/1.1 decoder
summary: >-
  A flaw was found in Netty's HTTP/1.1 decoder. This vulnerability allows a
  remote attacker to bypass `Transfer-Encoding` header validation by splitting
  the `Transfer-Encoding` field across multiple headers, with the last field
  containing …
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N'
cwe:
  - CWE-444
vendor: Red Hat
product: netty-codec-http
affected:
  - netty-codec-http (all versions)
  - netty-codec-http (all versions)
  - netty-codec-http (all versions)
  - netty-codec-http (all versions)
  - netty-codec-http (all versions)
  - netty-codec-http (all versions)
  - netty-codec-http (all versions)
  - netty-codec-http (all versions)
  - netty-codec-http
  - netty-codec-http
  - netty-codec-http (all versions)
  - netty-codec-http
published: '2026-09-18'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T11:17:00.790'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-93573'
references:
  - url: 'https://access.redhat.com/errata/RHSA-2026:69440'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:69470'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/security/cve/CVE-2026-93573'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2536964'
    label: secalert@redhat.com
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-93573.json
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-93573'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-93573'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-18T16:19:54.114434Z'
epss: 0.00578
epssPercentile: 0.45274
ingestedAt: '2026-09-18T15:44:31.580Z'
---

## Overview

A flaw was found in Netty's HTTP/1.1 decoder. This vulnerability allows a remote attacker to bypass `Transfer-Encoding` header validation by splitting the `Transfer-Encoding` field across multiple headers, with the last field containing a non-final transfer coding like `gzip` or `deflate`. This bypass can lead to HTTP request smuggling, enabling attackers to bypass security controls, desynchronize request processing, or cause requests to be processed in an unintended context.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat AMQ Broker 7, Red Hat AMQ Clients, Red Hat build of Apache Camel 4 for Quarkus 3, Red Hat build of Apache Camel for Spring Boot 4, Red Hat build of Apicurio Registry 3, Red Hat build of Debezium 3, … · no fix planned: Red Hat Fuse 7, Red Hat JBoss Enterprise Application Platform 7, Red Hat Single Sign-On 7, Red Hat AMQ Broker 7, … · updated 2026-09-24 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-93573.json)