Sensitive file sharing and restrictions in Jira

Description:
We want to check whether attachments in Jira can be restricted so that only selected users within the same project or issue can access specific files. Can we investigate if Jira permissions operate at the issue/work item level, not at the individual attachment level. This might impact saving any sensitive (e.g. Billable information or project with NDA) documents to be loaded in Jira.

Impact:
Sensitive documents cannot be selectively hidden from users who already have access to the parent issue.