The Side Effects of Being Smart: Safety Risks in MLLMs’ Multi-Image Reasoning

ACL ARR 2026 January Submission10027 Authors

06 Jan 2026 (modified: 20 Mar 2026)ACL ARR 2026 January SubmissionEveryoneRevisionsBibTeXCC BY 4.0
Keywords: AI Safety, Multimodal Large Language Models, Reasoning Robustness, Benchmark
Abstract: As Multimodal Large Language Models (MLLMs) acquire stronger reasoning capabilities to handle complex, multi-image instructions, this advancement may pose new safety risks. We study this problem by introducing MIR-SafetyBench, the first benchmark focused on multi-image reasoning safety, which consists of 2{,}676 instances across a taxonomy of 9 multi-image relations. Our extensive evaluations on 19 MLLMs reveal a troubling trend: models with more advanced multi-image reasoning can be more vulnerable on MIR-SafetyBench. Beyond attack success rates, we find that many responses labeled as safe are superficial, often driven by misunderstanding or evasive, non-committal replies. We further observe that unsafe generations exhibit lower attention entropy than safe ones on average. This internal signature suggests a possible risk that models may over-focus on task solving while neglecting safety constraints.
Paper Type: Long
Research Area: Safety and Alignment in LLMs
Research Area Keywords: Resources and Evaluation, Language Modeling, Multimodality and Language Grounding to Vision, Robotics and Beyond
Contribution Types: Model analysis & interpretability, Data resources, Data analysis
Languages Studied: English
Submission Number: 10027
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