ModSecurity
An open-source web application firewall engine that monitors and protects web applications against HTTP-based attacks
- Vendor
- OWASP Foundation
- Also known as
- modsecurity
Available worldwide
What is ModSecurity?
An open-source firewall module that monitors and controls HTTP traffic, providing customizable security rules and advanced protections against web application attacks. It serves as the foundation for many WAF implementations globally.
ModSecurity pricing
We don't have ModSecurity's full plan breakdown yet (its pricing page resisted automated reading). Here's what we could confirm. Always check live pricing for exact numbers.
What ModSecurity does
The capabilities that matter for waf, normalised so it lines up with every alternative. “-” means we haven't confirmed it, not that it's missing.
- Deployment model
- Self host
- Owasp top 10 protection
- ✓
- Custom rules engine
- ✓
- Bot management
- -
- API discovery protection
- -
- Ddos l7 protection
- -
- Rate limiting
- -
- Threat intel feeds
- -
- SIEM logging integration
- -
- Kubernetes ingress support
- -
- SOC2 type ii
- -
- PCI DSS compliant
- -
- Fedramp authorized
- -
- Pricing model
- Open source
Platform & deployment
Independently observed- On-premise
- Self-hosted
Integrations (1)
Independently observed- OWASP CRS•
Security & compliance
Known vulnerabilities: 0 (0 in the last 12 months) sourcea count reflects scale & disclosure, not quality
ModSecurity FAQ
Common questions about ModSecurity, answered from independent, dated evidence.
What is ModSecurity?
A flexible firewall module that monitors HTTP traffic and enforces security policies through a customizable rules engine. It is indexed under WAF.
Source: https://modsecurity.org/
Is ModSecurity free to use?
ModSecurity is open source, so it can be self-hosted and used at no licence cost. It is released under the Apache-2.0 licence. Pricing changes often, so verify at source before relying on it.
Source: https://modsecurity.org/
Can ModSecurity be self-hosted?
Yes. ModSecurity can be deployed self-hosted, so it does not have to run on the vendor's infrastructure.
Source: https://modsecurity.org/
What security certifications does ModSecurity have?
We have independently confirmed GDPR for ModSecurity. Certifications we do not list are ones we have not been able to verify from public sources, which is not the same as ModSecurity not holding them. Always confirm compliance directly before you rely on it.
Is ModSecurity open source?
Yes. ModSecurity is published under the Apache-2.0 licence, a permissive licence that generally allows commercial use and modification. Licence terms can change between releases, so verify against the repository for the version you intend to use.
ModSecurity alternatives
Other waf we track, ranked by the same independent score.
- Imperva WAFlow · 34%
- AWS WAFA cloud-based firewall service that protects web applications and APIs from attacks and DDoS threatsmedium · 73%
- Corazalow · 21%
- Fastly Next-Gen WAFmedium · 55%
- Cloudflare WAFWeb application security service that blocks malicious requests using managed and custom filtering rulesmedium · 74%
- Barracuda Web Application FirewallA network security solution that shields web applications and APIs from cyberattacks, bots, and intrusionslow · 45%
Compare ModSecurity
Side by side against other waf, attribute by attribute, with a source on every value.
The vioscaleAI score: one lens on the evidence
Not user reviews and not a paid placement: a confidence-weighted blend of the independent signals below (adoption, activity, security posture, and more), which you can sort and re-weight yourself. Vendors can correct their listing but can never move their rank, and stars are weighted low as a vanity metric. It is one way to read the evidence for ModSecurity, not the verdict.
| Signal | Score | Weight | Contribution | Evidence |
|---|---|---|---|---|
| Development activity | 50 | 0.09 | 4.7 | ✓ |
| Release cadence | 66 | 0.05 | 3.4 | ✓ |
| Capabilities | 46 | 0.06 | 2.9 | ✓ |
| Stars | 75 | 0.03 | 2.0 | ✓ |
| Integrations | 9 | 0.06 | 0.5 | ✓ |
| Dependent projects | 0 | 0.06 | 0.0 | ✓ |
| Security posture | 5 | 0.21 | 0.0 | - |
| Package downloads | 0 | 0.14 | 0.0 | - |
| Security score | 0 | 0.04 | 0.0 | - |
| Developer Q&A activity | 0 | 0.06 | 0.0 | - |
Computed . Re-weight it by intent, or see the full method.
All data & sourcesshow ↓
Every value we hold, with its source, retrieval date, and confidence. This is the evidence behind the score: don't trust it, verify it.
Activity
| Attribute | Value | Evidence |
|---|---|---|
| Commits last 30d | 38 | mediumsource · 2026-10-14 · 65% |
Adoption
Content
| Attribute | Value | Evidence |
|---|---|---|
| Faq | 5 items | mediumsource · 2026-09-10 · 69% |
Features
| Attribute | Value | Evidence |
|---|---|---|
| Capabilities | Pricing model: open_source · Deployment model: self_host · Custom rules engine: Yes · Owasp top 10 protection: Yes | mediumsource · 2026-10-14 · 60% |
Integrations
| Attribute | Value | Evidence |
|---|---|---|
| Count | 1 | mediumsource · 2026-10-14 · 60% |
Language
| Attribute | Value | Evidence |
|---|---|---|
| Primary | C++ | highsource · 2026-10-14 · 90% |
License
| Attribute | Value | Evidence |
|---|---|---|
| Spdx | Apache-2.0 | highsource · 2026-10-14 · 95% |
Market
| Attribute | Value | Evidence |
|---|---|---|
| Availability | HqCountry: US · PrimaryMarkets: … · AvailabilityScope: global · AvailableCountries: … · NotAvailableCountries: … | highsource · 2026-10-14 · 75% |
Pricing
Release
Security
| Attribute | Value | Evidence |
|---|---|---|
| Gdpr | Yes | highsource · 2026-08-19 · 75% |
| Vulnerabilities | Count: 0 · Source: https://advisories.ecosyste.ms/api/v1/advisories?ecosystem=gentoo&package_name=www-apache%2Fmod_security&per_page=100 · Last 12m: 0 | highsource · 2026-10-14 · 90% |
| Trust center | http://modsecurity.org/privacy-policy/ | mediumsource · 2026-10-14 · 60% |
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