Request Smuggling Vulnerability in Netty Framework
CVE-2026-42585

6.5MEDIUM

Key Information:

Vendor

Netty

Status
Netty
Netty-codec-http
Vendor
CVE Published:
13 May 2026

What is CVE-2026-42585?

The Netty framework, used for asynchronous network applications, exhibits a vulnerability that allows for malformed Transfer-Encoding headers to be improperly parsed. This flaw can lead to request smuggling attacks, where an attacker manipulates the HTTP request flow to bypass security controls or perform unauthorized actions. The issue affects versions prior to 4.2.13.Final and 4.1.133.Final, necessitating an immediate update to mitigate potential exploitation.

Affected Version(s)

netty >= 4.2.0.Alpha1, < 4.2.13.Final < 4.2.0.Alpha1, 4.2.13.Final

netty < 4.1.133.Final < 4.1.133.Final

netty-codec-http >= 4.2.0.Alpha1, < 4.2.13.Final < 4.2.0.Alpha1, 4.2.13.Final

References

https://github.com/netty/netty/security/advisories/GHSA-3...
x_refsource_CONFIRM

CVSS V3.1

Score:
6.5
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
Low
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.