The Shadow of JWT-Based Authentication: A Fatal Threat Behind the Convenience

**Executive Summary:** This report analyzes JWT authentication risks, documents multiple real CVEs and common attack techniques (algorithm confusion, alg=none, claim tampering, kid injection, hardcoded keys and key-rotation failures), and recommends mitigations including isolating signing keys in HSM/KMS, migrating to asymmetric keys (RS256), enforcing algorithm whitelists and strict claim validation, short-lived access tokens with refresh token strategies, centralized revocation, and enhanced logging/monitoring to detect abuse.