The ranking blended community consensus with classification of 6,639 catalogued incidents. Prompt Injection stays first with an explicit statement that no reliable prevention exists and that mitigations lower probability without reaching zero; Improper Output Handling falls to tenth because it is understood and fixable. New mappings tie each risk to NIST, CWE, MITRE ATLAS and the Agentic Top 10, and the boundary between the two lists is drawn at the point where the model becomes an actor with tools and memory.
What to do: re-baseline application security testing and questionnaires against the 2026 identifiers, apply the trifecta test to every agent, and treat output validation as a solved problem you are expected to have solved.
