CVE-2026-42578
Description
A flaw was found in Netty. The HttpProxyHandler component, which handles HTTP CONNECT requests, does not properly validate user-provided outbound headers. This allows an attacker to inject arbitrary HTTP headers into the CONNECT request sent to the proxy server. This could lead to unexpected behavior or potential bypass of security controls on the proxy server.
Statement
Important: This vulnerability in Netty's HttpProxyHandler allows for HTTP header injection into CONNECT requests when an attacker can influence outbound headers. The handler's explicit disabling of header validation could enable proxy-related attacks, such as cache poisoning or bypassing security controls, impacting applications utilizing this component.
Mitigation
Applications utilizing Netty's HttpProxyHandler must ensure that any user-controlled input used to populate outbound headers is rigorously sanitized to prevent CRLF injection. If comprehensive input sanitization cannot be implemented, restricting network access to the application that uses the HttpProxyHandler can reduce the attack surface.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.5 | 7.5 | 7.5 |
| Attack Vector | Network | Network | Network |
| Attack Complexity | Low | Low | Low |
| Privileges Required | None | None | None |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | None | None | None |
| Integrity Impact | High | High | High |
| Availability Impact | None | None | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Application Data
Frequently Asked Questions
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