Vulnerability · Published Dec 16, 2025 · Assigned by GitHub_M
CVE-2025-67735Netty has a CRLF Injection vulnerability in io.netty.handler.codec.http.HttpRequestEncoder
Medium 6.5
In plain English
A medium-severity security flaw in netty from netty. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 25% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | netty | 1:4.1.48-7+deb12u2 | DSA-6160-1 |
| Debian:12 | netty | 1:4.1.48-7+deb12u2 | DEBIAN-CVE-2025-67735 |
| Debian:13 | netty | 1:4.1.48-10+deb13u1 | DEBIAN-CVE-2025-67735 |
| Debian:13 | netty | 1:4.1.48-10+deb13u1 | DSA-6160-1 |
| Debian:14 | netty | 1:4.1.48-16 | DEBIAN-CVE-2025-67735 |
| Maven | io.netty:netty-codec-http | 4.1.129.Final | GHSA-84h7-rjj3-6jx4 |
| Maven | io.netty:netty-codec-http | 4.2.8.Final | GHSA-84h7-rjj3-6jx4 |
| Ubuntu:22.04:LTS | netty | 1:4.1.48-4+deb11u2ubuntu0.2 | USN-8654-1 |
| Ubuntu:22.04:LTS | netty | 1:4.1.48-4+deb11u2ubuntu0.2 | UBUNTU-CVE-2025-67735 |
| Ubuntu:24.04:LTS | netty | 1:4.1.48-9ubuntu0.2 | UBUNTU-CVE-2025-67735 |
| Ubuntu:24.04:LTS | netty | 1:4.1.48-9ubuntu0.2 | USN-8654-1 |
| Ubuntu:25.10 | netty | no fix listed | UBUNTU-CVE-2025-67735 |
| Ubuntu:26.10 | netty | no fix listed | UBUNTU-CVE-2025-67735 |
Affected products (as reported)
Weakness: CWE-93 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
References
- https://github.com/netty/netty/security/advisories/GHSA-84h7-rjj3-6jx4 x_refsource_CONFIRM