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API Security Resources

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A curated AppSec resource library covering XSS, SQLi, SSRF, IDOR, RCE, XXE, OSINT, and more.

API Security

API security addresses the unique vulnerabilities that arise when applications expose functionality through programmatic interfaces. As organizations shift to API-first architectures, microservices, and third-party integrations, APIs have become the primary attack surface for modern applications. The OWASP API Security Top 10 identifies critical risks including Broken Object Level Authorization (BOLA), mass assignment, excessive data exposure, and lack of rate limiting. APIs often inadvertently expose more data than their UI counterparts, accept parameters that bypass frontend validation, and may lack the authentication and authorization checks that browser-based interfaces enforce. REST, GraphQL, gRPC, and WebSocket APIs each present distinct security challenges. Effective API security requires authentication hardening, input validation, output filtering, rate limiting, proper error handling, and comprehensive logging across every endpoint.

Date Added Link Excerpt
2026-04-22 NEW 2026A Deep Dive on the Most Critical API Vulnerability: BOLAA Deep Dive on the Most Critical API Vulnerability: BOLA
2026-04-22 NEW 2026What Is Broken Object Property Level Authorization?What Is Broken Object Property Level Authorization?
2026-04-22 NEW 2026What Is Broken Object Level Authorization?What Is Broken Object Level Authorization?
2026-04-22 NEW 2026This Is How I Hacked an API Using Mass Assignment VulnerabilityThis Is How I Hacked an API Using Mass Assignment Vulnerability
2026-04-22 NEW 2026CVE-2026-34839: CORS Vulnerability in Glances REST APICVE-2026-34839: CORS Vulnerability in Glances REST API
2026-04-22 NEW 2026API ThreatStats Report 2026API ThreatStats Report 2026
2026-04-22 NEW 2026VAmPI: Vulnerable REST API with OWASP Top 10 VulnerabilitiesVAmPI: Vulnerable REST API with OWASP Top 10 Vulnerabilities
2026-04-22 NEW 2026API4:2023 Unrestricted Resource ConsumptionAPI4:2023 Unrestricted Resource Consumption
2026-04-22 NEW 20261H 2026 State of AI and API Security Report (Salt)1H 2026 State of AI and API Security Report (Salt)
2026-04-22 NEW 2026PortSwigger Lab: Exploiting a Mass Assignment VulnerabilityPortSwigger Lab: Exploiting a Mass Assignment Vulnerability
2026-04-19 NEW 2026BOLA API Attack & Prevention — StackHawkBOLA API Attack & Prevention — StackHawk
2026-04-19 NEW 2026Broken Object-Level Authorization (BOLA): What It Is and How to Prevent ItBroken Object-Level Authorization (BOLA): What It Is and How to Prevent It
2026-04-19 NEW 2026OWASP Top 10 API Security Risks and How to Mitigate Them — PyntOWASP Top 10 API Security Risks and How to Mitigate Them — Pynt
2026-04-19 NEW 2026OWASP Top 10 2025: Latest Changes and EnhancementsOWASP Top 10 2025: Latest Changes and Enhancements
2026-04-19 NEW 2026OWASP API Security Top 10 Vulnerabilities — 2025OWASP API Security Top 10 Vulnerabilities — 2025
2026-04-16 NEW 2026MCP Access Control: OPA vs Cedar - NatomaMCP Access Control: OPA vs Cedar - Natoma
2026-04-16 NEW 2026Stateful REST API Fuzzing with RESTlerStateful REST API Fuzzing with RESTler
2026-04-16 NEW 2026Inside Modern API Attacks: 2026 API ThreatStats Report - WallarmInside Modern API Attacks: 2026 API ThreatStats Report - Wallarm
2026-04-16 NEW 2026OWASP API Security Testing FrameworkOWASP API Security Testing Framework
2026-04-16 NEW 2026Kong API Gateway Misconfigurations Case Study - Trend MicroKong API Gateway Misconfigurations Case Study - Trend Micro
2026-04-16 NEW 2026API Security Testing: Tools and Techniques - API7.aiAPI Security Testing: Tools and Techniques - API7.ai
2026-04-16 NEW 2026BOLA and BFLA: The API Vulnerabilities That Silently Expose DataBOLA and BFLA: The API Vulnerabilities That Silently Expose Data
2026-04-16 NEW 2026API Penetration Testing: Complete GuideAPI Penetration Testing: Complete Guide
2026-04-16 NEW 2026How to Protect APIs from OWASP Authorization Risks: BOLA, BOPLA and BFLA - 42CrunchHow to Protect APIs from OWASP Authorization Risks: BOLA, BOPLA and BFLA - 42Crunch
2026-04-16 NEW 2026Securing the Gates: Mastering BOLA and BFLA in API SecuritySecuring the Gates: Mastering BOLA and BFLA in API Security
2026-04-11 2026Exploiting API4: 8 Real-World Unrestricted Resource Consumption Attack ScenariosExploiting API4: 8 Real-World Unrestricted Resource Consumption Attack Scenarios
2026-04-11 2026Exploiting Server-Side Request Forgery in an APIExploiting Server-Side Request Forgery in an API
2026-04-11 2026API Versioning Vulnerabilities: Deprecated Endpoints Still Accepting RequestsAPI Versioning Vulnerabilities: Deprecated Endpoints Still Accepting Requests
2026-04-11 2026Exploiting JWT Vulnerabilities: Advanced Exploitation GuideExploiting JWT Vulnerabilities: Advanced Exploitation Guide
2026-04-11 2026openapi-fuzzer: Black-box Fuzzer for OpenAPI Specificationsopenapi-fuzzer: Black-box Fuzzer for OpenAPI Specifications
2026-04-11 2026CATS: REST API Fuzzer and Negative Testing ToolCATS: REST API Fuzzer and Negative Testing Tool
2026-04-11 2026RESTler: Stateful REST API Fuzzing ToolRESTler: Stateful REST API Fuzzing Tool
2026-04-11 2026BFLA: Broken Function Level AuthorizationBFLA: Broken Function Level Authorization
2026-04-11 2026API Gateway Authorizers: Vulnerable By DesignAPI Gateway Authorizers: Vulnerable By Design
2026-04-11 2026HTTP Request Smuggling in API GatewaysHTTP Request Smuggling in API Gateways
2026-04-11 2026Kong API Gateway Misconfigurations: A Security Case StudyKong API Gateway Misconfigurations: A Security Case Study
2026-04-11 2026Swagger-EZ: Pentesting APIs Using OpenAPI DefinitionsSwagger-EZ: Pentesting APIs Using OpenAPI Definitions
2026-04-11 2026APIDetector: Scan for Exposed Swagger EndpointsAPIDetector: Scan for Exposed Swagger Endpoints
2026-04-11 2026Autoswagger: Automated Discovery and Testing of OpenAPI and Swagger EndpointsAutoswagger: Automated Discovery and Testing of OpenAPI and Swagger Endpoints
2026-04-11 2026Swagger Jacker: Auditing OpenAPI Definition FilesSwagger Jacker: Auditing OpenAPI Definition Files
2026-04-11 2026PayloadsAllTheThings: API Key LeaksPayloadsAllTheThings: API Key Leaks
2026-04-11 2026State of Secrets: 28 Million Credentials Leaked on GitHub in 2025State of Secrets: 28 Million Credentials Leaked on GitHub in 2025
2026-04-11 2026Bypassing Rate Limits: All Known TechniquesBypassing Rate Limits: All Known Techniques
2026-04-11 2026Rate Limit Bypass - HackTricksRate Limit Bypass - HackTricks
2026-04-11 2026Hacking APIs: Bypassing Rate LimitingHacking APIs: Bypassing Rate Limiting
2026-04-11 2026What is Mass Assignment? Attacks and Security TipsWhat is Mass Assignment? Attacks and Security Tips
2026-04-11 2026API Security 101: Mass Assignment and Exploitation in the WildAPI Security 101: Mass Assignment and Exploitation in the Wild
2026-04-11 2026What is BOLA? 3-digit bounty from TopcoderWhat is BOLA? 3-digit bounty from Topcoder
2026-04-11 2026API1:2023 Broken Object Level AuthorizationAPI1:2023 Broken Object Level Authorization
2026-04-11 2026Exposing a New BOLA Vulnerability in GrafanaExposing a New BOLA Vulnerability in Grafana
2026-04-10 2026API Exploitation For Bug BountyAPI Exploitation For Bug Bounty
2026-04-10 2026API Penetration Testing Roadmap (2025)API Penetration Testing Roadmap (2025)
2026-04-10 2026API Security Testing Tool Checklist (2026)API Security Testing Tool Checklist (2026)
2026-04-10 2026GraphQL Security Best Practices: A Developer's GuideGraphQL Security Best Practices: A Developer's Guide
2026-04-10 2026OWASP API Security Top 10 RisksOWASP API Security Top 10 Risks
2026-04-10 2026API Security Reality Check: Q2 2025 API ThreatStats ReportAPI Security Reality Check: Q2 2025 API ThreatStats Report
2026-04-10 2026GraphQL Security Testing: Complete GuideGraphQL Security Testing: Complete Guide
2026-04-10 2026Common API Security Vulnerabilities & Solutions (2026 Guide)Common API Security Vulnerabilities & Solutions (2026 Guide)
2026-04-10 2026Common Attacks on REST APIs and GraphQL APIsCommon Attacks on REST APIs and GraphQL APIs
2026-04-10 2026GraphQL API Security: Common Vulnerabilities and ExploitsGraphQL API Security: Common Vulnerabilities and Exploits
2026-04-10 2026Introduction - OWASP Top 10:2025Introduction - OWASP Top 10:2025
2026-04-10 2026OWASP Top 10:2025OWASP Top 10:2025
2026-04-10 2026API Security Risks: The 10 Most Exploited in 2026API Security Risks: The 10 Most Exploited in 2026
2026-04-10 2026What Are the OWASP Top 10 API Security Risks? - AkamaiWhat Are the OWASP Top 10 API Security Risks? - Akamai
2026-04-10 2026OWASP API Security Top 10 (2025) Guide with TestsOWASP API Security Top 10 (2025) Guide with Tests
2026-04-10 2026OWASP Top 10 2025: What's Changed and WhyOWASP Top 10 2025: What's Changed and Why
2026-04-10 2026Top 10 OWASP API Security in 2026Top 10 OWASP API Security in 2026
2026-04-10 2026OWASP Top Ten 2025: Key Security Risks for APIsOWASP Top Ten 2025: Key Security Risks for APIs
2026-04-10 2026OWASP API Security: Top 10 Risks & Remedies for 2026OWASP API Security: Top 10 Risks & Remedies for 2026
2026-04-06 2026Protecting Payment, Cart, and Login Endpoints at the EdgeProtecting Payment, Cart, and Login Endpoints at the Edge
2026-04-06 2026Open Banking API Security: The Complete Guide in 2026Open Banking API Security: The Complete Guide in 2026
2026-04-06 2026Enhancing REST API Fuzzing with Access Policy Violation DetectionEnhancing REST API Fuzzing with Access Policy Violation Detection
2026-04-06 20266 Ways to Protect Your Spring Boot APIs from Common Attacks6 Ways to Protect Your Spring Boot APIs from Common Attacks
2026-04-06 20267 Identity and API Security Tools Modern SaaS Teams Should Evaluate in 20267 Identity and API Security Tools Modern SaaS Teams Should Evaluate in 2026
2026-04-03 2026InQL - GraphQL Scanner | PortSwigger BApp StoreInQL - GraphQL Scanner | PortSwigger BApp Store
2026-04-03 2026OWASP API Security Top 10 Explained | Salt SecurityOWASP API Security Top 10 Explained | Salt Security
2026-04-03 2026How To Prepare For An API Penetration TestHow To Prepare For An API Penetration Test
2026-04-03 2026Awesome GraphQL Security - Curated List of ResourcesAwesome GraphQL Security - Curated List of Resources
2026-04-03 2026API Testing with Burp Suite: A Practical GuideAPI Testing with Burp Suite: A Practical Guide
2026-04-03 2026Top 6 API Pentesting Tools | CobaltTop 6 API Pentesting Tools | Cobalt
2026-04-03 2026API Attack Awareness: BOLA - Why It Tops the OWASP API Top 10API Attack Awareness: BOLA - Why It Tops the OWASP API Top 10
2026-04-03 2026GraphQL API Vulnerabilities | Web Security AcademyGraphQL API Vulnerabilities | Web Security Academy
2026-04-03 2026API Testing | Web Security AcademyAPI Testing | Web Security Academy
2026-04-03 2026OWASP API Security Top 10OWASP API Security Top 10
2026-04-03 2026OWASP API Security Project | OWASP FoundationThe API Security project focuses on strategies and solutions to understand and mitigate the unique vulnerabilities and security risks of Application Programming Interfaces (APIs)

Frequently Asked Questions

What is the OWASP API Security Top 10?
The OWASP API Security Top 10 is a list of the most critical API security risks, including Broken Object Level Authorization (BOLA), Broken Authentication, Broken Object Property Level Authorization, Unrestricted Resource Consumption, Broken Function Level Authorization, Server Side Request Forgery, Security Misconfiguration, and Lack of Protection from Automated Threats.
Why are APIs harder to secure than web applications?
APIs often expose more data and functionality than web UIs, accept complex input formats, lack the natural access controls of a browser interface, and are harder to monitor. They also tend to grow organically, creating shadow APIs that bypass security controls, and their machine-to-machine nature makes abuse detection more difficult.
What tools are used for API security testing?
Common tools include Burp Suite with API-focused extensions, Postman for manual testing, OWASP ZAP for automated scanning, Akto for API inventory and testing, and custom scripts for fuzzing API parameters. For GraphQL APIs, InQL and graphql-cop are essential. API specification files (OpenAPI/Swagger) are valuable for understanding and testing the full attack surface.

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