CVE-2026-42578

7.5 HIGH
Published: May 13, 2026 Modified: May 18, 2026
View on NVD

Description

Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, Netty's HttpProxyHandler constructs HTTP CONNECT requests with header validation explicitly disabled. The newInitialMessage() method creates headers using DefaultHttpHeadersFactory.headersFactory().withValidation(false), then adds user-provided outboundHeaders without any CRLF validation. This allows an attacker who can influence the outbound headers to inject arbitrary HTTP headers into the CONNECT request sent to the proxy server. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://github.com/netty/netty/security/advisories/GHSA-45q3-82m4-75jr
Source: security-advisories@github.com
Exploit Mitigation Vendor Advisory
https://github.com/netty/netty/security/advisories/GHSA-45q3-82m4-75jr
Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
Exploit Mitigation Vendor Advisory

2 reference(s) from NVD

Quick Stats

CVSS v3 Score
7.5 / 10.0
EPSS (Exploit Probability)
0.4%
32th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

netty