How Vulnerable Are AI Agents to Indirect Prompt Injections? Insights from a Large-Scale Public Competition. - Mateusz Dziemian; Maxwell Lin; Xiaohan Fu; Micha Nowak; Nick Winter; Eliot Krzysztof Jones; Andy Zou; Lama Ahmad; Kamalika Chaudhuri; Sahana Chennabasappa; Xander Davies; Lauren Deason; et al. (CoRR, 2026)