> A common misconception about the Linux kernel is that it's secure, or that users can go a long time without worrying about security updates. Neither of these are even remotely true. New versions of Linux are released almost every week, often containing important security fixes among the other changes. These releases typically don't make explicit mention of which commits have security implications. As a result, many "stable" or "LTS" distributions don't know which commits should be backported to their old kernels, or even that something needs backporting at all. If the problem has a CVE assigned to it, maybe your distribution will pick it up. Maybe not. Even if a CVE exists, at least in the case of Ubuntu and Debian especially, users are often left with kernels full of known holes for months at a time. Red Hat and similar "enterprise" distros have the same problem and have been called out publicly about it on more than one occasion. Moreover, the Linux kernel security team doesn't request CVEs for any vulnerabilities, partly because there are just too many to track. Downstream's culture of trying to cherrypick security fixes in the name of stability does not work. Arch doesn't play the backporting game, instead opting to provide the newest stable kernels shortly after their upstream release.
[1]: https://vez.mrsk.me/linux-hardening.html (lots of linked sources in the actual paragraph there)