SAST + LLM Hybrid Pipeline: Semgrep + LLM Post-Processing Reduces False Positives by 91% — Precision Jumps from 35.7% to 89.5%, 11× Signal-to-Noise Improvement

InfoWorld·high signal

A hybrid SAST framework combining Semgrep's deterministic scanning with LLM-based validation achieved 89.5% precision versus Semgrep's 35.7% baseline and GPT-4's standalone 65.5%. False positives dropped from 225 to 20 (11× improvement), and average triage time for security analysts decreased by 91%. The LLM layer evaluates execution context, data flow, and validation patterns to determine actual exploitability — catching multi-file dataflow bugs that traditional scanners miss entirely.