Atlassian urges customers to take 'immediate action' to protect against flaw
techcrunch.com
techcrunch.com
If you're hosting the servers yourself, not the datacenter versions, then you need to be very careful about how much you upgrade.
Jira, yes, you can upgrade that to the latest version, which is 9.11.
I did the same with Bitbucket and after the upgrade it told me that I have a server license but need a datacenter license for this latest version, which is 8.15. You can only upgrade up to 8.14 [0]. Luckily the downgrade from 8.15 to 8.14 is easy and there are instructions for it [1].
So I checked the upgrade matrix for Confluence [2] to make sure that I won't have the same issues as with Bitbucket, but these huge, tremendous idiots at Atlassian don't mention a single word about 8.5 being the last version to support server licenses, all above that requires datacenter licenses. I say idiots, because in the upgrade matrix from Bitbucket they highlight this requirement with bold text, in the one from Confluence they don't even care mention it.
[0] https://confluence.atlassian.com/bitbucketserver/upgrade-mat...
[1] https://confluence.atlassian.com/bitbucketserver/downgrade-b...
[2] https://confluence.atlassian.com/doc/confluence-upgrade-matr...
[3] https://confluence.atlassian.com/doc/confluence-8-5-release-...