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 )
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 )
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 )
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 )
In general, a standard system update will make all the necessary changes.
The problem can be corrected by updating your system to the following package versions:
Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines.
The full story
This article is one source in a clustered incident — the cluster page carries the summary, timeline and every other outlet covering it.
