Samsung has started to release the October Android update for many Galaxy smartphones and tablets. The update resolves numerous security issues which is why owners of compatible devices are advised to install the update in a timely manner.
https://www.notebookcheck.net/Samsung-starts-to-roll-out-the-October-2021-security-update-for-Galaxy-S21-Note-20-Z-Fold-3-and-many-more-Galaxy-smartphones.570160.0.html