snapd 2.54.2 and earlier created ~/snap directories in user home directories without specifying owner-only permissions. This could allow a local attacker to read information that should have been private. Fixed in snapd versions 2.54.3+18.04, 2.54.3+20.04 and 2.54.3+21.10.1
https://ubuntu.com/security/notices/USN-5292-1
https://github.com/snapcore/snapd/commit/7d2a966620002149891446a53cf114804808dcca
https://github.com/snapcore/snapd/commit/6bcaeeccd16ed8298a301dd92f6907f88c24cc85