Best WAF for Nginx

ModSecurity with the OWASP Core Rule Set has been the default WAF for Nginx for over a decade. It runs as a native Nginx module via the modsecurity-nginx connector and inspects every request inside the worker process. The CRS provides thousands of curated rules covering SQL injection (942xxx), XSS (941xxx), PHP injection (933xxx), and RCE. Setup is the hard part: compiling from source takes work, and CRS tuning avoids false positives. NGINX Plus users get dynamic module loading. For a full walkthrough, see our ModSecurity on Nginx guide.

nginx-app-protect is F5 WAF for NGINX. F5 owns Nginx, and this is their commercial WAF that runs as a dynamic NGINX Plus module. Uses F5 threat intelligence and bot signatures alongside OWASP CRS. If you already run NGINX Plus, this integrates without changing your architecture: no reverse proxy, no sidecar, just a module directive. Requires a NGINX Plus license and an F5 WAF subscription. Not available for NGINX Open Source.

NAXSI is the purist's Nginx WAF. Compiles as a dynamic or static Nginx module, written in C with only libpcre as a dependency. Uses a scoring system that flags suspicious characters (angle brackets, SQL keywords, pipe characters) instead of pattern-matching attacks. No rule updates, no CRS to maintain. Tradeoff: more tuning with learning mode. Archived in 2023 but has an active fork by wargio. See our Nginx WAF hardening guide for NAXSI setup.

Cloudflare works with any Nginx deployment regardless of version or modules. No compilation, no nginx.conf changes. Point DNS at Cloudflare and traffic is filtered at the edge. Managed ruleset catches SQL injection, XSS, and path traversal. Free tier covers basics. Pro ($20/mo) unlocks full OWASP CRS and custom rules.

Coraza runs as a reverse proxy or sidecar in front of Nginx. Uses the same OWASP CRS rules as ModSecurity. Written in Go, handles high concurrency without competing with Nginx for CPU. Tradeoff: an extra hop in the request path. Works well in containers. See our Coraza on Nginx Docker guide or migrate to Caddy + Coraza.

BunkerWeb wraps Nginx, ModSecurity, OWASP CRS, CrowdSec, and a management UI into one Docker container. Deploy as a reverse proxy in front of your existing Nginx, or replace Nginx entirely. Web UI for WAF management without nginx.conf editing.

open-appsec compiles as an Nginx module and uses ML instead of regex. No CRS to download, no rules to tune. Microsecond inference per request with weekly threat model updates. Simpler than ModSecurity: enable the module and let it learn.

CrowdSec combines an app-layer WAF with a community IP blocklist. The Nginx bouncer module blocks flagged IPs. The AppSec component adds HTTP request inspection. Works alongside any other Nginx WAF as a second layer. Community blocklist fed by thousands of installations.

SafeLine uses semantic analysis to understand HTTP request intent. Deploy as a Docker reverse proxy in front of Nginx. Dashboard for monitoring blocked requests, certificates, and rate limiting with zero config.

Fastly Next-Gen WAF (Signal Sciences) uses signals and thresholds instead of regex. Deploy as a CDN edge WAF in front of Nginx, or run the agent on your server. Signal-based approach means fewer false positives than CRS.

Imperva provides enterprise cloud WAF for Nginx backends via DNS proxy. Includes advanced bot management and API security. Suited for organizations needing PCI DSS, SOC 2, and 24/7 SOC support.