Published Dec 16, 2025Sources checked Oct 28, 2026
6.5MEDIUMCVSS out of 10
What this means
Review the available evidence
CVE-2025-67735 and is rated Medium severity with a CVSS score of 6.5. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.
CISA KEVNot listedBased on the latest collected catalog
EPSS0.3%Estimated 30-day exploitation probability
Ransomware useNot markedCISA KEV ransomware field
Threat actors0Source-linked actor relationships
Overview
What is CVE-2025-67735?
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.