Kong Gateway WAF vs ModSecurity Open Source WAF
Kong Gateway WAF and ModSecurity Open Source WAF take different approaches to web application security. Consider your team's expertise and infrastructure preferences when evaluating these options.
Kong Gateway WAF and ModSecurity Open Source WAF take fundamentally different approaches to web application security. Understanding your infrastructure and team capabilities will help determine which approach fits your needs.
Overview
Kong Gateway WAF and ModSecurity Open Source WAF are both popular web application firewall solutions. This comparison will help you understand the key differences and choose the right one for your needs.
API gateway with built-in WAF plugin for enterprise customers. Kong is the most popular open source API gateway (35K+ GitHub stars, 312M+ downloads) built on NGINX, processing 400B+ API calls daily. The WAF plugin is an Enterprise-only add-on that protects API endpoints at the gateway layer.
The original open source WAF engine powering countless applications, offering unmatched flexibility for those willing to manage their own security infrastructure.
Quick Comparison
| Feature | Kong Gateway WAF | ModSecurity Open Source WAF |
|---|---|---|
| Overall Rating | 3.8/5 | 4.0/5 |
| Free Tier | No | Yes |
| Pricing Model | Tiered (Plus per-gateway + Enterprise custom) | Free (Open Source) |
| Ease of Use | 3.2/5 | 2.5/5 |
| Value for Money | 3.0/5 | 4.8/5 |
| Support | 4.2/5 | 3.0/5 |
| Open Source | No | Yes |
| Platforms | Linux (Ubuntu, RHEL, Debian, Amazon Linux, Alpine), Docker, Kubernetes (via Ingress Controller and Operator), AWS, Azure, GCP, ARM64, macOS (dev) | Apache, Nginx, IIS, Kubernetes (via Ingress), Docker, any platform via libmodsecurity |
| Compliance | SOC 2 Type II, FIPS 140-2 (Enterprise data planes), supports PCI DSS and HIPAA compliance | N/A (varies by implementation) |
Pricing Comparison
Kong Gateway WAF
Model: Tiered (Plus per-gateway + Enterprise custom)
Kong Gateway OSS
Free
Kong Konnect Plus
From $225/mo
Kong Konnect Enterprise
Custom (annual)
Dedicated Cloud Gateway
$500/mo per control plane + $0.15/GB
ModSecurity Open Source WAF
Model: Free (Open Source)
Free Tier AvailableCommunity Edition
Free
Commercial Support
Varies by vendor
Features Comparison
Kong Gateway WAF
-
Gateway-Embedded WAF
WAF runs as a plugin inside the Kong Gateway process, inspecting API traffic at the same layer where routing, authentication, and rate limiting occur. No separate WAF appliance or additional proxy hop needed.
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OWASP Top 10 Protection
Built-in protection against common web application attacks including SQL injection, cross-site scripting, command injection, and path traversal at the API gateway layer.
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Plugin Ecosystem
Over 100 plugins for security, traffic control, authentication, and observability. WAF works alongside bot detection, IP restriction, CORS, ACL, and rate limiting plugins in a configurable execution chain.
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Third-Party WAF Integrations
Open plugin architecture supports third-party WAF engines including open-appsec (ML-driven detection) and Wallarm (API security). Teams can choose the WAF engine that fits their threat model.
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Kubernetes-Native Deployment
Kong Ingress Controller and Kong Kubernetes Operator provide native Kubernetes integration. WAF policies can be managed declaratively through Kubernetes CRDs alongside gateway configuration.
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Hybrid Mode
Cloud-managed control plane with self-hosted data planes. WAF policies are centrally managed and distributed to data planes running in any environment, including air-gapped networks.
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AI Gateway
Dedicated AI gateway capabilities including LLM proxy, token-based rate limiting, semantic caching, PII sanitization, prompt guardrails, and MCP server proxy. WAF protects AI endpoints alongside traditional APIs.
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Declarative Configuration
Gateway and WAF configuration can be managed as code through declarative YAML/JSON, enabling GitOps workflows and CI/CD pipeline integration for security policy changes.
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Advanced Rate Limiting
Enterprise-grade rate limiting with sliding window counters, consumer groups, and cluster-wide synchronization. Works in conjunction with WAF to prevent both application-layer attacks and abuse.
ModSecurity Open Source WAF
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OWASP Core Rule Set
Comprehensive, community-maintained rule set providing protection against OWASP Top 10 and more.
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Custom Rules
Powerful SecRule language for creating custom detection logic based on any request/response attribute.
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Real-Time Request Analysis
Inspect and analyze every HTTP transaction with access to full request and response data.
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Audit Logging
Detailed logging of security events for forensics, compliance, and monitoring.
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Virtual Patching
Create temporary rules to protect against vulnerabilities while permanent fixes are developed.
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Data Loss Prevention
Inspect response bodies to prevent sensitive data leakage.
Which One Is Right for You?
The best WAF depends on your specific requirements, infrastructure, and team expertise.
Kong Gateway WAF
- You need: Organizations already using Kong as their API gateway, Kubernetes-native architectures needing gateway-level WAF, teams wanting unified API management and security in one platform, enterprises with microservices architectures routing all traffic through an API gateway
- You're using: Linux (Ubuntu, RHEL, Debian, Amazon Linux, Alpine), Docker, Kubernetes (via Ingress Controller and Operator), AWS, Azure, GCP, ARM64, macOS (dev)
ModSecurity Open Source WAF
- You need: Security teams with WAF expertise, organizations with strict budget constraints, those needing maximum customization, educational purposes
- You want to start with a free tier
- You prefer open-source solutions
- You're using: Apache, Nginx, IIS, Kubernetes (via Ingress), Docker, any platform via libmodsecurity
We recommend evaluating both options with a trial or free tier before committing. Consider your existing infrastructure, team expertise, compliance requirements, and budget.
Frequently Asked Questions
Which is better for startups: Kong Gateway WAF or ModSecurity Open Source WAF?
ModSecurity Open Source WAF offers a free tier while Kong Gateway WAF does not, making ModSecurity Open Source WAF more accessible for budget-conscious startups. Kong Gateway WAF scores higher for ease of use (3.2/5), which is valuable for smaller teams. Consider your immediate security needs and growth plans when choosing.
Which has better support: Kong Gateway WAF or ModSecurity Open Source WAF?
Kong Gateway WAF has a higher support rating (4.2/5) compared to ModSecurity Open Source WAF (3.0/5). However, support quality can vary based on your plan tier - enterprise customers typically receive more responsive support from both providers. Consider evaluating support during a trial period.
Which is easier to implement: Kong Gateway WAF or ModSecurity Open Source WAF?
Kong Gateway WAF scores higher for ease of use (3.2/5) versus ModSecurity Open Source WAF (2.5/5). The actual implementation effort depends on your existing infrastructure and team expertise.
Which is more cost-effective: Kong Gateway WAF or ModSecurity Open Source WAF?
ModSecurity Open Source WAF offers a free tier while Kong Gateway WAF requires a paid plan. ModSecurity Open Source WAF scores higher for value (4.8/5). Total cost depends on your traffic volume, required features, and support level needs.
Which works better with AWS: Kong Gateway WAF or ModSecurity Open Source WAF?
Kong Gateway WAF explicitly supports AWS while ModSecurity Open Source WAF's AWS integration may vary. Consider whether native AWS integration or cross-cloud portability matters more for your use case.