Update Python sub-version in conda base

I currently have Python 3.8.12 installed. I’ve been advised to update to 3.8.18 as there are security vulnerabilities in the older versions. I know that updating to a later full release in the base environment is a bad idea, but surely it must be possible to update through 3.8.x versions? However sudo apt install python3 just returns python3 is already the newest version (3.10.6-1~22.04) and conda update python just returns

Collecting package metadata (current_repodata.json): - WARNING conda.models.version:get_matcher(556): Using .* with relational operator is superfluous and deprecated and will be removed in a future version of conda. Your spec was 1.7.1.*, but conda is ignoring the .* and treating it as 1.7.1
done
Solving environment: done

# All requested packages already installed.

So it seems to think that it’s fully up to date, but it’s still on a version that’s a couple of years old.