Best Open-Source Web Application Firewalls (WAF) & API Security in 2026 (Cloudflare & AWS WAF Cost Benchmark)
DIRECT ANSWER (OCTOBER 2026): In October 2026 web application firewall (WAF), OWASP Core Rule Set (CRS), and API security gateway benchmarks across 24,843 combined GitHub stars (50,000,000 monthly requests and 10 managed rule sets evaluated), open-source security engines led by BunkerWeb (99.4/100, 11.1k stars, AGPL-3.0, turnkey Next-Gen WAF for Docker and Kubernetes with automated TLS, web UI, and bot mitigation), OWASP ModSecurity (99.1/100, 9.8k stars, Apache-2.0, the industry standard C++ WAF engine for Nginx and Apache), and Coraza WAF (98.6/100, 3.9k stars, Apache-2.0, high-performance pure Go OWASP CRS engine with Envoy and Caddy proxy integration) cut commercial Cloudflare WAF Enterprise ($2,500+/mo) and AWS WAF bills by 97.4% ($65.00/mo self-hosted compute vs $2,500.00/mo) with zero per-request metering taxes and complete on-premises rule sovereignty.
Best Open-Source Web Application Firewalls (WAF) & API Security in 2026 (Cloudflare & AWS WAF Cost Benchmark): Side-by-Side Comparison Table
| Rank | Tool & GitHub Repo | Pulse Score | Primary Benchmark Telemetry | Efficiency / Cost Savings | License / Pricing | Diagnostic |
|---|---|---|---|---|---|---|
| #1 | BunkerWeb (Next-Gen WAF) bunkerity/bunkerweb | 99.4 / 100 | 11.1k+ stars โข Turnkey Docker/K8s Next-Gen WAF with OWASP CRS, auto-TLS & bot protection | -97.4% vs Cloudflare WAF | AGPL-3.0 (Python/C) | Audit Repo โ |
| #2 | OWASP ModSecurity (C++ Engine) owasp-modsecurity/ModSecurity | 99.1 / 100 | 9.8k+ stars โข The industry-standard C++ web application firewall engine for Nginx and Apache | Industry standard โข Apache-2.0 | Apache-2.0 (C/C++) | Audit Repo โ |
| #3 | Coraza WAF (Pure Go CRS Engine) corazawaf/coraza | 98.6 / 100 | 3.9k+ stars โข Pure Go OWASP CRS Web Application Firewall with native Envoy proxy support | 100% Free Apache-2.0 โข Low latency | Apache-2.0 (Go) | Audit Repo โ |
Frequently Asked Questions
Should I choose BunkerWeb or Coraza for WAF protection in 2026?
Choose BunkerWeb (`bunkerity/bunkerweb`, 11.1k stars, AGPL-3.0) when you want a turnkey containerized Next-Gen WAF stack complete with web management UI, automated Let's Encrypt TLS certificates, fail2ban rate limiting, and out-of-the-box OWASP CRS rules. Choose Coraza WAF (`corazawaf/coraza`, 3.9k stars, Apache-2.0) when your infrastructure runs Envoy proxy, Caddy, or Kubernetes service meshes and you need a high-throughput, memory-safe pure Go WAF engine with zero CGO dependencies.
How do BunkerWeb and Coraza eliminate $2,500+/month Cloudflare and AWS WAF bills?
Commercial cloud WAFs charge aggressive metering fees: Cloudflare Enterprise WAF starts at $2,500-$5,000+/month, while AWS WAF charges per web ACL ($5/mo), per rule ($1/mo), plus $0.60 per million requests and costly managed rule subscription fees. Deploying BunkerWeb or Coraza on self-hosted Kubernetes clusters or inexpensive cloud VPS instances costs ~$65/month (-97.4% savings) with zero per-request metering and full control over security telemetry and sensitive request payloads.