Publication Type

Conference Proceeding Article

Version

acceptedVersion

Publication Date

1-2026

Abstract

Recent advances in reasoning-centric models promise improved robustness through mechanisms such as chain-of-thought prompting and test-time scaling. However, their ability to withstand gaslighting negation attacks—adversarial prompts that confidently deny correct answers—remains underexplored. In this paper, we conduct a systematic evaluation of three state-of-the-art reasoning models, i.e., OpenAI’s o4-mini, Claude-3.7-Sonnet and Gemini-2.5-Flash, across three multimodal benchmarks: MMMU, MathVista, and CharXiv. Our evaluation reveals significant accuracy drops (25–29% on average) following gaslighting negation attacks, indicating that even top-tier reasoning models struggle to preserve correct answers under manipulative user feedback. Built upon the insights of the evaluation and to further probe this vulnerability, we introduce GaslightingBench-R, a new diagnostic benchmark specifically designed to evaluate reasoning models’ susceptibility to defend their belief under gaslighting negation attacks. Constructed by filtering and curating 1,025 challenging samples from the existing benchmarks, GaslightingBench-R induces even more dramatic failures, with accuracy drops exceeding 53% on average. Our findings highlight a fundamental gap between step-by-step reasoning and resistance to adversarial manipulation, calling for new robustness strategies that safeguard reasoning models against gaslighting negation attacks. Additional details are available on our project page: https://binzhubz.github.io/GaslightingBench-R/.

Keywords

Gaslighting negation attacks, Multimodal reasoning, Reasoning models

Discipline

Artificial Intelligence and Robotics | Information Security | Software Engineering

Research Areas

Data Science and Engineering

Publication

Multimedia Modeling: 32nd International Conference on Multimedia Modeling, MMM 2026, Prague, Czech Republic, January 29-31, Proceedings

First Page

188

Last Page

202

ISBN

9789819569595

Identifier

10.1007/978-981-95-6960-1_14

Publisher

Springer

City or Country

Cham

Additional URL

https://doi.org/10.1007/978-981-95-6960-1_14

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