Security updates are applied only to the most recent release.
Since this is a file encryption software, if you find a security vulnerability, please report it privately. Reporting it in public issues must be avoided as a courtesy for existing user, so that the maintainer can fixed the issue before any bad actors exploit the program.
While reporting any issue, the reporter must provide proper explanation why they consider something as an issue. They may also need to provide proper resolution steps.
This project is maintained by a solo Author, and so when a issue is reported it will be addressed on a reasonable-effort basis. There is no time limit when an issue will be fixed.