CVE-2025-67735
December 16, 2025
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.
Affected Packages
https://github.com/netty/netty.git (GITHUB):
Affected version(s) >=netty-4.2.0.Alpha1 <netty-4.2.8.FinalFix Suggestion:
Update to version netty-4.2.8.Finalhttps://github.com/netty/netty.git (GITHUB):
Affected version(s) >=netty-3.2.4.Final <netty-4.1.129.FinalFix Suggestion:
Update to version netty-4.1.129.Finalio.netty:netty-codec-http (JAVA):
Affected version(s) >=4.2.0.Alpha1 <4.2.8.FinalFix Suggestion:
Update to version 4.2.8.Finalio.netty:netty-codec-http (JAVA):
Affected version(s) >=4.0.0.Alpha1 <4.1.129.FinalFix Suggestion:
Update to version 4.1.129.FinalRelated Resources (4)
Do you need more information?
Contact UsCVSS v4
Base Score:
6.9
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
LOW
Vulnerable System Integrity
LOW
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
6.5
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Weakness Type (CWE)
Improper Neutralization of CRLF Sequences ('CRLF Injection')
EPSS
Base Score:
0.03
