Fix MySQL Authentication Plugin Errors

Last updated: August 28, 2026.

Authentication plugin errors usually mean the account and client do not support the same method. Inspect the account first, then update the client or account deliberately instead of weakening server security globally.

Inspect and update the account

SELECT user, host, plugin
FROM mysql.user
WHERE user = 'app_user';

ALTER USER 'app_user'@'10.%'
  IDENTIFIED WITH caching_sha2_password BY 'Use-a-new-secret';

Resolve the mismatch safely

• Upgrade the database driver when it lacks current plugin support.
• Use TLS for remote authentication.
• Match the user and host row actually selected by MySQL.
• Test with a dedicated least-privilege account.
• Do not enable an older plugin server-wide as the first response.

Reference: MySQL 8.4 authentication plugin reference.