# CVE-2026-42581: Netty: HTTP/1.0 TE+CL Coexistence Bypasses Smuggling Sanitization

> CVE-2026-42581: Netty: HTTP/1.0 TE+CL Coexistence Bypasses Smuggling Sanitization. CVSS 5.8 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2026-42581
Last updated: 2026-09-18T13:18:20Z

- Published: 2026-05-13 17:54 UTC · Updated: 2026-09-18 13:18 UTC · Assigner: GitHub\_M
- CVSS: 5.8 (CVSS 3.1) · Severity: Medium · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
- EPSS: 0.63%, 50th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-444

## Description

Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, HttpObjectDecoder strips a conflicting Content-Length header when a request carries both Transfer-Encoding: chunked and Content-Length, but only for HTTP/1.1 messages. The guard is absent for HTTP/1.0. An attacker that sends an HTTP/1.0 request with both headers causes Netty to decode the body as chunked while leaving Content-Length intact in the forwarded HttpMessage. Any downstream proxy or handler that trusts Content-Length over Transfer-Encoding will disagree on message boundaries, enabling request smuggling. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.

## Affected vendors and products

- netty: netty
- Red Hat: Red Hat AMQ Broker 7.13.6
- Red Hat: Red Hat AMQ Broker 7.14.1
- Red Hat: Red Hat AMQ Clients
- Red Hat: Red Hat build of Apache Camel 4.18.1.P1 for Spring Boot 3.5.16
- Red Hat: Red Hat build of Apache Camel 4 for Quarkus 3
- Red Hat: Red Hat build of Apicurio Registry 3
- Red Hat: Red Hat build of Debezium 3
- Red Hat: Red Hat Build of Keycloak
- Red Hat: Red Hat Data Grid 8
- Red Hat: Red Hat Enterprise Linux AI (RHEL AI) 3
- Red Hat: Red Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 7
- Red Hat: Red Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 8
- Red Hat: Red Hat JBoss Enterprise Application Platform 8.1.7.GA
- Red Hat: Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 10
- Red Hat: Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8
- Red Hat: Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9
- Red Hat: streams for Apache Kafka 2
- Red Hat: Streams for Apache Kafka 3.2.1

## Tracked companies

- [Jira](https://rewindex.com/company/jira.md)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-42581)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-42581)
- [https://github.com/netty/netty/security/advisories/GHSA-xxqh-mfjm-7mv9](https://github.com/netty/netty/security/advisories/GHSA-xxqh-mfjm-7mv9)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2026-42581 · Markdown: https://rewindex.com/cve/CVE-2026-42581.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-42581 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T03:12:42.951Z