If you are running Ubuntu 23.10, you need to upgrade to Ubuntu 24.04 LTS by July 11, 2024, if you want to continue receiving security updates. While Linux is a pretty secure operating system, it’s still not a good idea to use an OS that is no longer receiving security patches.
While you’ll probably be alright just after security updates end, the longer you wait the more vulnerable your system will become. Ubuntu upgrades are straightforward, fast, and hassle-free so it’s best to do a backup of your data now and get updated.
What’s nice about Ubuntu 24.04 LTS is that it’s supported for five years so if you don’t want to upgrade again soon, you don’t need to. You could even skip Ubuntu 26.04 LTS and wait for Ubuntu 28.04 LTS in 2028 before upgrading if you like.
As an interim release, Ubuntu 23.10 (Mantic Minotaur) is only supported for nine months in contrast to five years for long-term releases. Ubuntu 23.10 came out on October 12, 2023, so nine months put the end of life date at July 11.
Ubuntu 23.10 acted as a foundation version for Ubuntu 24.04 LTS. It introduced the new App Center to make it easier to find new apps. It also had preview support for hardware-backed full-disk encryption. The new App Center was designed to be fast, intuitive, and user-friendly with support for both snap and deb package formats. The new App Center also grabbed rich metadata from the Canonical Snap Store to show more information about apps users search for.
Canonical also made a security change in that update so that the kernel would support an additional mode that forces programs to use an AppArmor Profile where they use unprivileged user namespaces. This helped to address significant security vulnerabilities.
To upgrade to Ubuntu 24.04 LTS, just open the Update Manager and you should see a message telling you to upgrade. You can read more here.
Source: Ubuntu