JWT Algorithm Confusion Attacks: How CVE-2026-22817, CVE-2026-27804, and CVE-2026-23552 Work and How to Fix Them
JWT algorithm confusion attacks are back — and Q1 2026 has seen a cluster of critical CVEs across major frameworks and libraries. The root cause is always the same: trusting the attacker-controlled alg field in the JWT header to select the signature verification algorithm. This guide explains exactly how these attacks work, walks through the three most impactful 2026 CVEs, and gives you concrete, language-specific fixes you can apply today. ...