KnowledgeDeliver Zero-Day: When Hard-Coded Keys Break Every Deployment
GTIG and Mandiant detail active exploitation of CVE-2026-5426, an unauthenticated RCE in the KnowledgeDeliver LMS. Identical hard-coded ASP.NET machineKey values let attackers forge ViewState payloads against any internet-facing instance, deploying the BLUEBEAM web shell and Cobalt Strike BEACON.