Ubuntu USN · USN-8406-1

Net::CIDR::Lite vulnerabilities

Published: Mon, 08 Jun 2026 16:06

CVE-2026-40198CVE-2021-47154CVE-2026-40199

Summary

Several security issues were fixed in Net::CIDR::Lite.

Details

Dave Rolsky discovered that Net::CIDR::Lite did not properly handle extraneous zero characters at the beginning of an IP address string. A remote attacker could possibly use this issue to bypass access controls that are based on IP addresses. This issue only affected Ubuntu 16.04 LTS and Ubuntu 18.04 LTS. (CVE-2021-47154) It was discovered that Net::CIDR::Lite did not properly validate the IPv6 group count when handling uncompressed IPv6 addresses. A remote attacker could possibly use this issue to bypass access controls. (CVE-2026-40198) It was discovered that Net::CIDR::Lite mishandled IPv4 mapped IPv6 addresses. A remote attacker could possibly use this issue to bypass access controls that are based on IP addresses. (CVE-2026-40199)

Recommended actions per Ubuntu release

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

Ubuntu bionic

libnet-cidr-lite-perl→0.21-1ubuntu0.18.04.1~esm1apt_upgrade_esm
Fixed at 0.21-1ubuntu0.18.04.1~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 libnet-cidr-lite-perl=0.21-1ubuntu0.18.04.1~esm1
```
Sign up at https://ubuntu.com/pro. Free for personal + small-team use.
libnet-cidr-lite-perl→0.21-1ubuntu0.18.04.1~esm1apt_upgrade_esm
Fixed at 0.21-1ubuntu0.18.04.1~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 libnet-cidr-lite-perl=0.21-1ubuntu0.18.04.1~esm1
```
Sign up at https://ubuntu.com/pro. Free for personal + small-team use.

Ubuntu focal

libnet-cidr-lite-perl→0.21-2ubuntu0.1+esm1apt_upgrade
Standard apt upgrade. Install 0.21-2ubuntu0.1+esm1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y libnet-cidr-lite-perl
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
libnet-cidr-lite-perl→0.21-2ubuntu0.1+esm1apt_upgrade
Standard apt upgrade. Install 0.21-2ubuntu0.1+esm1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y libnet-cidr-lite-perl
```
Most apt upgrades restart their service automatically. needrestart lists anything else.

Ubuntu jammy

libnet-cidr-lite-perl→0.22-1ubuntu0.1apt_upgrade
Standard apt upgrade. Install 0.22-1ubuntu0.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y libnet-cidr-lite-perl
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
libnet-cidr-lite-perl→0.22-1ubuntu0.1apt_upgrade
Standard apt upgrade. Install 0.22-1ubuntu0.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y libnet-cidr-lite-perl
```
Most apt upgrades restart their service automatically. needrestart lists anything else.

Ubuntu noble

libnet-cidr-lite-perl→0.22-2ubuntu0.24.04.1apt_upgrade
Standard apt upgrade. Install 0.22-2ubuntu0.24.04.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y libnet-cidr-lite-perl
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
libnet-cidr-lite-perl→0.22-2ubuntu0.24.04.1apt_upgrade
Standard apt upgrade. Install 0.22-2ubuntu0.24.04.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y libnet-cidr-lite-perl
```
Most apt upgrades restart their service automatically. needrestart lists anything else.

Ubuntu questing

libnet-cidr-lite-perl→0.22-2ubuntu0.25.10.1apt_upgrade
Standard apt upgrade. Install 0.22-2ubuntu0.25.10.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y libnet-cidr-lite-perl
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
libnet-cidr-lite-perl→0.22-2ubuntu0.25.10.1apt_upgrade
Standard apt upgrade. Install 0.22-2ubuntu0.25.10.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y libnet-cidr-lite-perl
```
Most apt upgrades restart their service automatically. needrestart lists anything else.

Ubuntu resolute

libnet-cidr-lite-perl→0.22-2ubuntu0.26.04.1apt_upgrade
Standard apt upgrade. Install 0.22-2ubuntu0.26.04.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y libnet-cidr-lite-perl
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
libnet-cidr-lite-perl→0.22-2ubuntu0.26.04.1apt_upgrade
Standard apt upgrade. Install 0.22-2ubuntu0.26.04.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y libnet-cidr-lite-perl
```
Most apt upgrades restart their service automatically. needrestart lists anything else.

Ubuntu xenial

libnet-cidr-lite-perl→0.21-1ubuntu0.16.04.1~esm1apt_upgrade_esm
Fixed at 0.21-1ubuntu0.16.04.1~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 libnet-cidr-lite-perl=0.21-1ubuntu0.16.04.1~esm1
```
Sign up at https://ubuntu.com/pro. Free for personal + small-team use.
libnet-cidr-lite-perl→0.21-1ubuntu0.16.04.1~esm1apt_upgrade_esm
Fixed at 0.21-1ubuntu0.16.04.1~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 libnet-cidr-lite-perl=0.21-1ubuntu0.16.04.1~esm1
```
Sign up at https://ubuntu.com/pro. Free for personal + small-team use.

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