ALPC, or Advanced Local Procedure Call, is a Windows inter-process communication mechanism. It lets system services, user processes, and security-critical components exchange messages efficiently while enforcing access checks and session boundaries.
In cyber security, ALPC matters because it sits close to the Windows trust boundary. Many privilege-escalation and sandbox-escape bugs target ALPC endpoints, message parsing, or the brokered services behind them. If an attacker already has code running on a machine, ALPC can provide a path to higher privileges by abusing a vulnerable service or malformed message. Defenders treat ALPC issues as high priority because they often affect core OS functionality, are hard to isolate, and may be reachable from low-privilege code. Hardening and patching these interfaces reduces the chance that a foothold turns into full system compromise.