Permission boundaries are the access limits that define what a system, user, or automation is allowed to view, modify, or execute. They are a core part of least-privilege design: each component gets only the rights it needs, and no more. In security products, especially agentic tools that can take action on their own, permission boundaries determine whether the software can only recommend a response or can also isolate hosts, change settings, or open tickets.
These boundaries matter because over-permissioned systems are easier to abuse. If an attacker compromises a tool with broad access, they may be able to pivot into other services, delete data, or weaken defenses. Strong boundaries reduce blast radius and make misconfigurations less dangerous. Defenders enforce them with scoped roles, approval steps, segmentation, and continuous auditing so that every action stays inside authorized limits.