# CVE-2025-67735: libnetty-java: Netty is an asynchronous, event-driven network application framework

CVE-2025-67735 is fixed in 2 products on 1 platform, first by libnetty-java 1:4.1.7-4ubuntu0.1+esm7, released December 15, 2025. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2025-67735
- Priority: Routine
- CVSS: 6.5 (Medium)
- EPSS: 0.0032
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Dec 15, 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | libnetty-java Ubuntu 18.04.6 LTS (bionic) | 1:4.1.7-4ubuntu0.1+esm7 | [libnetty-java 1:4.1.7-4ubuntu0.1+esm7](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libnetty-java-1-4.1.7-4ubuntu0.1-esm7.md) | Dec 15, 2025 |
| Linux | libnetty-java Ubuntu 20.04 LTS (focal) | 1:4.1.45-1ubuntu0.1~esm7 | [libnetty-java 1:4.1.45-1ubuntu0.1~esm7](https://patchblox.com/security/data/fix/linux/ubuntu-focal-libnetty-java-1-4.1.45-1ubuntu0.1-esm7.md) | Dec 15, 2025 |
| Linux | libnetty-java Ubuntu 22.04.1 LTS (jammy) | 1:4.1.48-4+deb11u2ubuntu0.2+esm1 | [libnetty-java 1:4.1.48-4+deb11u2ubuntu0.2+esm1](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-libnetty-java-1-4.1.48-4-deb11u2ubuntu0.2-esm1.md) | Dec 15, 2025 |
| Linux | libnetty-java Ubuntu 24.04.5 LTS (noble) | 1:4.1.48-9ubuntu0.2+esm1 | [libnetty-java 1:4.1.48-9ubuntu0.2+esm1](https://patchblox.com/security/data/fix/linux/ubuntu-noble-libnetty-java-1-4.1.48-9ubuntu0.2-esm1.md) | Dec 15, 2025 |
| Linux | netty Debian 12.15 (bookworm) | 1:4.1.48-7+deb12u2 | [DEBIAN-CVE-2025-67735](https://patchblox.com/security/data/fix/linux/debian-cve-2025-67735.md) | Dec 16, 2025 |
| Linux | netty Debian 13.5 (trixie) | 1:4.1.48-10+deb13u1 | [DEBIAN-CVE-2025-67735](https://patchblox.com/security/data/fix/linux/debian-cve-2025-67735.md) | Dec 16, 2025 |
| Linux | netty Debian 14 | 1:4.1.48-16 | [DEBIAN-CVE-2025-67735](https://patchblox.com/security/data/fix/linux/debian-cve-2025-67735.md) | Dec 16, 2025 |
| Linux | netty opensuse-leap 15.6 | 4.1.130-150200.4.40.1 | [SUSE-SU-2025:4489-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4489-1.md) | Dec 19, 2025 |
| Linux | netty sles 15.7 | 4.1.130-150200.4.40.1 | [SUSE-SU-2025:4489-1](https://patchblox.com/security/data/fix/linux/suse-su-2025-4489-1.md) | Dec 19, 2025 |

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Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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