Ubuntu USN · USN-8401-1

Netty vulnerabilities

Published: Mon, 08 Jun 2026 13:38

CVE-2026-42586CVE-2026-42579CVE-2026-42585CVE-2026-42581CVE-2026-42584CVE-2026-42578

Summary

Several security issues were fixed in Netty.

Details

It was discovered that Netty's HTTP proxy handler did not properly validate headers when constructing CONNECT requests. An attacker could possibly use this issue to inject arbitrary HTTP headers into CONNECT requests. This issue only affected Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, and Ubuntu 26.04 LTS. (CVE-2026-42578) It was discovered that Netty's DNS codec did not properly enforce domain name constraints. An attacker could possibly use this issue to bypass domain name validation, or cause Netty to consume resources, leading to a denial of service. This issue only affected Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, and Ubuntu 26.04 LTS. (CVE-2026-42579) It was discovered that Netty did not correctly handle HTTP/1.0 requests containing both a Transfer-Encoding and Content-Length header. A remote attacker could possibly use this issue to perform HTTP request smuggling attacks. (CVE-2026-42581) Violeta Georgieva discovered that Netty incorrectly paired responses with requests when handling informational HTTP responses. A remote attacker could possibly use this issue to perform HTTP request smuggling attacks. (CVE-2026-42584) Violeta Georgieva discovered that Netty incorrectly parsed malformed Transfer-Encoding headers. A remote attacker could possibly use this issue to perform HTTP request smuggling attacks. (CVE-2026-42585) It was discovered that Netty's Redis encoder did not validate CRLF characters. An attacker could possibly use this issue to inject arbitrary Redis commands. This issue only affected Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, and Ubuntu 26.04 LTS. (CVE-2026-42586)

Recommended actions per Ubuntu release

StackPatch playbook auto-generated per release codename and per affected package.

Ubuntu bionic

netty→1:4.1.7-4ubuntu0.1+esm6apt_upgrade
Standard apt upgrade. Install 1:4.1.7-4ubuntu0.1+esm6 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y netty
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
libnetty-java→1:4.1.7-4ubuntu0.1+esm6apt_upgrade
Standard apt upgrade. Install 1:4.1.7-4ubuntu0.1+esm6 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y libnetty-java
```
Most apt upgrades restart their service automatically. needrestart lists anything else.

Ubuntu focal

netty→1:4.1.45-1ubuntu0.1~esm6apt_upgrade_esm
Fixed at 1:4.1.45-1ubuntu0.1~esm6 — ESM-only. Enable Ubuntu Pro (free for 5 personal machines) or treat as watch item.
```
sudo pro attach <token>
sudo apt-get update
sudo apt-get install --only-upgrade -y netty=1:4.1.45-1ubuntu0.1~esm6
```
Sign up at https://ubuntu.com/pro. Free for personal + small-team use.
libnetty-java→1:4.1.45-1ubuntu0.1~esm6apt_upgrade_esm
Fixed at 1:4.1.45-1ubuntu0.1~esm6 — ESM-only. Enable Ubuntu Pro (free for 5 personal machines) or treat as watch item.
```
sudo pro attach <token>
sudo apt-get update
sudo apt-get install --only-upgrade -y libnetty-java=1:4.1.45-1ubuntu0.1~esm6
```
Sign up at https://ubuntu.com/pro. Free for personal + small-team use.

Ubuntu jammy

netty→1:4.1.48-4+deb11u2ubuntu0.1+esm3apt_upgrade
Standard apt upgrade. Install 1:4.1.48-4+deb11u2ubuntu0.1+esm3 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y netty
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
libnetty-java→1:4.1.48-4+deb11u2ubuntu0.1+esm3apt_upgrade
Standard apt upgrade. Install 1:4.1.48-4+deb11u2ubuntu0.1+esm3 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y libnetty-java
```
Most apt upgrades restart their service automatically. needrestart lists anything else.

Ubuntu noble

netty→1:4.1.48-9ubuntu0.1+esm3apt_upgrade
Standard apt upgrade. Install 1:4.1.48-9ubuntu0.1+esm3 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y netty
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
libnetty-java→1:4.1.48-9ubuntu0.1+esm3apt_upgrade
Standard apt upgrade. Install 1:4.1.48-9ubuntu0.1+esm3 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y libnetty-java
```
Most apt upgrades restart their service automatically. needrestart lists anything else.

Ubuntu resolute

netty→1:4.1.48-16ubuntu0.1~esm2apt_upgrade_esm
Fixed at 1:4.1.48-16ubuntu0.1~esm2 — ESM-only. Enable Ubuntu Pro (free for 5 personal machines) or treat as watch item.
```
sudo pro attach <token>
sudo apt-get update
sudo apt-get install --only-upgrade -y netty=1:4.1.48-16ubuntu0.1~esm2
```
Sign up at https://ubuntu.com/pro. Free for personal + small-team use.
libnetty-buffer-java→1:4.1.48-16ubuntu0.1~esm2apt_upgrade_esm
Fixed at 1:4.1.48-16ubuntu0.1~esm2 — ESM-only. Enable Ubuntu Pro (free for 5 personal machines) or treat as watch item.
```
sudo pro attach <token>
sudo apt-get update
sudo apt-get install --only-upgrade -y libnetty-buffer-java=1:4.1.48-16ubuntu0.1~esm2
```
Sign up at https://ubuntu.com/pro. Free for personal + small-team use.
libnetty-common-java→1:4.1.48-16ubuntu0.1~esm2apt_upgrade_esm
Fixed at 1:4.1.48-16ubuntu0.1~esm2 — ESM-only. Enable Ubuntu Pro (free for 5 personal machines) or treat as watch item.
```
sudo pro attach <token>
sudo apt-get update
sudo apt-get install --only-upgrade -y libnetty-common-java=1:4.1.48-16ubuntu0.1~esm2
```
Sign up at https://ubuntu.com/pro. Free for personal + small-team use.
libnetty-java→1:4.1.48-16ubuntu0.1~esm2apt_upgrade_esm
Fixed at 1:4.1.48-16ubuntu0.1~esm2 — ESM-only. Enable Ubuntu Pro (free for 5 personal machines) or treat as watch item.
```
sudo pro attach <token>
sudo apt-get update
sudo apt-get install --only-upgrade -y libnetty-java=1:4.1.48-16ubuntu0.1~esm2
```
Sign up at https://ubuntu.com/pro. Free for personal + small-team use.

Ubuntu trusty

netty→1:3.2.6.Final-2+deb8u2ubuntu0.1~esm1apt_upgrade_esm
Fixed at 1:3.2.6.Final-2+deb8u2ubuntu0.1~esm1 — ESM-only. Enable Ubuntu Pro (free for 5 personal machines) or treat as watch item.
```
sudo pro attach <token>
sudo apt-get update
sudo apt-get install --only-upgrade -y netty=1:3.2.6.Final-2+deb8u2ubuntu0.1~esm1
```
Sign up at https://ubuntu.com/pro. Free for personal + small-team use.
libnetty-java→1:3.2.6.Final-2+deb8u2ubuntu0.1~esm1apt_upgrade_esm
Fixed at 1:3.2.6.Final-2+deb8u2ubuntu0.1~esm1 — ESM-only. Enable Ubuntu Pro (free for 5 personal machines) or treat as watch item.
```
sudo pro attach <token>
sudo apt-get update
sudo apt-get install --only-upgrade -y libnetty-java=1:3.2.6.Final-2+deb8u2ubuntu0.1~esm1
```
Sign up at https://ubuntu.com/pro. Free for personal + small-team use.

Ubuntu xenial

netty→1:4.0.34-1ubuntu0.1~esm4apt_upgrade_esm
Fixed at 1:4.0.34-1ubuntu0.1~esm4 — ESM-only. Enable Ubuntu Pro (free for 5 personal machines) or treat as watch item.
```
sudo pro attach <token>
sudo apt-get update
sudo apt-get install --only-upgrade -y netty=1:4.0.34-1ubuntu0.1~esm4
```
Sign up at https://ubuntu.com/pro. Free for personal + small-team use.
libnetty-java→1:4.0.34-1ubuntu0.1~esm4apt_upgrade_esm
Fixed at 1:4.0.34-1ubuntu0.1~esm4 — ESM-only. Enable Ubuntu Pro (free for 5 personal machines) or treat as watch item.
```
sudo pro attach <token>
sudo apt-get update
sudo apt-get install --only-upgrade -y libnetty-java=1:4.0.34-1ubuntu0.1~esm4
```
Sign up at https://ubuntu.com/pro. Free for personal + small-team use.

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