CVE-2025-67735

Netty has a CRLF Injection vulnerability in io.netty.handler.codec.http.HttpRequestEncoder

State: Published
Severity: 6.5 Medium
Published: Dec 16, 2025
Updated: Dec 16, 2025
Reserved: Dec 11, 2025

Description

Netty is an asynchronous, event-driven network application framework. In versions prior to 4.1.129.Final and 4.2.8.Final, the `io.netty.handler.codec.http.HttpRequestEncoder` has a CRLF injection with the request URI when constructing a request. This leads to request smuggling when `HttpRequestEncoder` is used without proper sanitization of the URI. Any application / framework using `HttpRequestEncoder` can be subject to be abused to perform request smuggling using CRLF injection. Versions 4.1.129.Final and 4.2.8.Final fix the issue.

Scores

CVSS	Score	Vector	Source
3.1	6.5 Medium	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N	GitHub_M

Weaknesses

CWE-93 Improper Neutralization of CRLF Sequences ('CRLF Injection')

Affected Products

Product	Versions
nettynetty	>= 4.2.0.Alpha1, < 4.2.8.FinalAffected < 4.1.129.FinalAffected

References

https://github.com/netty/netty/security/advisories/GHSA-84h7-rjj3-6jx4

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