A user changing their email after signing up and verifying it can change it without verification in profile settings. The configuration option "verify_email_enabled" will only validate email only on sign up.
https://grafana.com/security/security-advisories/cve-2023-6152/
https://github.com/grafana/bugbounty/security/advisories/GHSA-3hv4-r2fm-h27f