EC
2027
MariaDBERRORCommonAccess ControlHIGH confidence

Column-level access denied

Production Risk

High — application cannot access required columns.

What this means

The current user does not have the required privilege on the specified column. MySQL supports column-level grants (SELECT, INSERT, UPDATE, REFERENCES) for fine-grained access control.

Why it happens
  1. 1Column-level privilege required but not granted.
  2. 2User has table-level SELECT but a column was explicitly restricted with a REVOKE at the column level.
  3. 3Application accessing a column it has not been granted access to.
How to reproduce
trigger — this will error
trigger — this will error
SELECT salary FROM employees; -- user lacks SELECT on salary column

expected output

ERROR 2027 (42000): SELECT command denied to user 'app'@'%' for column 'salary' in table 'employees'.

Fix 1

Grant column-level access

Grant column-level access
GRANT SELECT (id, name) ON mydb.employees TO 'app'@'%';

Why this works

Column-level grants allow precise control over which columns are accessible.

Fix 2

Use a view to expose only permitted columns

Use a view to expose only permitted columns
CREATE VIEW emp_public AS SELECT id, name FROM employees;
GRANT SELECT ON mydb.emp_public TO 'app'@'%';

Why this works

A view abstracts column restrictions behind a simple interface.

What not to do

✕

Sources
Official documentation ↗

MySQL 8.0 — 2027 ER_COLUMNACCESS_DENIED_ERROR

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