From what I understand ImageMagick's vulnerability management involves updating to newer versions, so this is specifically about distributions that don't. Ubuntu chooses to distribute older versions with their own patches, but require Pro for you to get them.
With that said, the mentioned vulnerability is an odd one. A CVE published in 2023 with a CVE number for 2022 for a bug that was found and fixed in 2020. The bug in question is a memory leak when passing -help.[1]