CVE-2025-67735
Netty has a CRLF Injection vulnerability in io.netty.handler.codec.http.HttpRequestEncoder
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.
INFO
Published Date :
Dec. 16, 2025, 1:15 a.m.
Last Modified :
Jan. 2, 2026, 6:50 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update Netty to version 4.1.129.Final or later.
- Update Netty to version 4.2.8.Final or later.
- Sanitize request URIs if updating is not possible.
Public PoC/Exploit Available at Github
CVE-2025-67735 has a 2 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-67735.
| URL | Resource |
|---|---|
| https://github.com/netty/netty/security/advisories/GHSA-84h7-rjj3-6jx4 | Exploit Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-67735 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-67735
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
None
Go
Kafka sink for Kusto
kafka-connector azure-data-explorer kusto
Java Shell
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-67735 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2025-67735 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Jan. 02, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:* versions up to (excluding) 4.1.129 *cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:* versions from (including) 4.2.0 up to (excluding) 4.2.8 Added Reference Type GitHub, Inc.: https://github.com/netty/netty/security/advisories/GHSA-84h7-rjj3-6jx4 Types: Exploit, Vendor Advisory -
New CVE Received by [email protected]
Dec. 16, 2025
Action Type Old Value New Value Added 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. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N Added CWE CWE-93 Added Reference https://github.com/netty/netty/security/advisories/GHSA-84h7-rjj3-6jx4