Comprehensive JWT Security Guide
Comprehensive JWT Security Guide 🆕 Updated September 12, 2026 — added the PAN-OS/Panorama CAS algorithm-confusion bypass (CVE-2026-0265) and how a config precondition leaking pre-auth turns patching into a real priority list. A practitioner’s reference for JSON Web Token security – vulnerabilities, exploitation techniques, attack vectors, implementation flaws, and defense strategies. Covers algorithm confusion, signature bypass, header injection, key confusion, library-specific issues, cryptographic attacks, attack chaining, and secure implementation patterns. 🧪 Try it live: Practice these attacks hands-on in the JWT Attack Playground — forge alg:none, RS256→HS256 algorithm confusion, and weak-secret tokens, then fire them at a configurable verifier to see what a vulnerable vs. secure server does. Runs 100% in your browser. ...