A security principle stating that subjects (users, processes, systems) should be granted the minimum set of access rights necessary to perform their legitimate duties, and no more.

Principle

Privileges are minimized and granted on a need-to-perform basis, preferably with defaults of denial and continuous review; separation and least escalation are used to limit the blast radius of faults and compromises.

Demonstration

An operating system runs services under distinct, unprivileged accounts; a database exposes only required columns via a restricted view to an application; container runtimes drop capabilities not needed by the contained process.

Misapplication

Applying excessive restriction that breaks legitimate workflows (e.g., denying essential inter-process communication) or implementing coarse-grained roles that either overprivilege or are so fine-grained they become unmanageable and lead to insecure workarounds.

Consequence

When applied appropriately, the attack surface and potential impact of compromise are reduced, auditing is simplified, and containment of faults becomes tractable; combined with defense-in-depth it improves security posture.

Reversal

A policy of blanket full privileges or permissive defaults (maximum privilege) which eases operation in the short term but increases systemic risk and the scope of possible damage from misconfiguration or breach.

Boundary

Applies to authorization and capability assignment across users, processes, services, and devices; it does not prescribe authentication mechanisms, key management practices, or guarantee immunity from attacker privilege escalation if other vulnerabilities exist.

Semantic Tension

Tension exists between least privilege and usability, rapid development, or operational convenience; also between least privilege and emergency 'break-glass' needs where temporary elevation is required.

Synthesis

The principle of least privilege is a governance rule to minimize granted rights to those strictly needed, implemented through role design, capability restriction, default-deny, and monitoring—balanced against operational needs to avoid counterproductive friction.