Ultra vires
beyond the powers
Where the phrase comes from
Company law and administrative law. An act that sits outside the powers given by a statute, a charter, or a constitution can be void even if everyone in the room wanted it.
What lawyers are pointing at
The question is the instrument that grants the power, read with the limits in that instrument. Usefulness is not a grant. A board, a minister, or a city council acting past the grant does not get a pass because the project was popular. The remedy depends on the field: a company act and a public-law act are not treated identically. The Latin names the defect. It does not pick the remedy by itself.
The same shape in code
An IAM policy, a sudoers line, and an API scope are the grant. A job that can write outside that list is ultra vires the moment it does so, including when the write 'fixes' something. Widen the grant in the policy, in the open, or do not do the write.
A concrete picture
A statute lets an agency license wells. The agency issues a rule about school curricula. The curriculum rule is ultra vires the licensing statute, however sensible the rule looks.