Replacing Checkmarx with Open Source — Designing an AppSec Stack from SAST, SCA, IaC, and Secrets

No single open-source tool replaces Checkmarx one to one. The realistic answer is a loosely coupled multi-engine setup: place a dedicated OSS scanner in each functional category and bind them with a management layer like DefectDojo. This article walks through the Semgrep CE versus Opengrep split in SAST, Trivy-centered SCA, Checkov and KICS for IaC, Gitleaks and TruffleHog for secrets, and DefectDojo's deduplication and Jira sync, as of 2026, along with the limits such as legacy languages and supply-chain risk.