Shuhang Lin


2025

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Disentangling Logic: The Role of Context in Large Language Model Reasoning Capabilities
Wenyue Hua | Kaijie Zhu | Lingyao Li | Lizhou Fan | Mingyu Jin | Shuhang Lin | Haochen Xue | Zelong Li | Jindong Wang | Yongfeng Zhang
Findings of the Association for Computational Linguistics: ACL 2025

This study intends to systematically disentangle pure logic reasoning and text understanding by investigating the contrast across abstract and contextualized logical problems from a comprehensive set of domains. We explore whether LLMs demonstrate genuine reasoning capabilities across various domains when the underlying logical structure remains constant. We focus on two main questions (1) Can abstract logical problems alone accurately benchmark LLMs’ reasoning ability in real-world scenarios, disentangled from contextual support in practical settings? (2) Does fine-tuning LLMs on abstract logic problems generalize to contextualized logic problems and vice versa? To investigate these questions, we focus on standard propositional logic, specifically propositional deductive and abductive logic reasoning. We construct datasets for both reasoning types with four difficulty levels across 12 distinct domains based on the Wikipedia categorization in addition to those with purely abstract variables. Our experiments aim to provide insights into disentangling context in logical reasoning, the genuine reasoning capabilities of LLMs, and their generalization potential. Coda and data are available at https://anonymous.4open.science/r/ContextHub-957E.

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Invisible Prompts, Visible Threats: Malicious Font Injection in External Resources for Large Language Models
Junjie Xiong | Changjia Zhu | Shuhang Lin | Chong Zhang | Yongfeng Zhang | Yao Liu | Lingyao Li
Findings of the Association for Computational Linguistics: EMNLP 2025

Large Language Models (LLMs) are increasingly equipped with capabilities of real-time web search and integrated with protocols like the Model Context Protocol (MCP). This extension could introduce new security vulnerabilities. We present a systematic investigation of LLM vulnerabilities to hidden adversarial prompts through malicious font injection in external resources like webpages, where attackers manipulate code-to-glyph mapping to inject deceptive content which are invisible to users. We evaluate two critical attack scenarios: (1) malicious content relay and (2) sensitive data leakage through MCP-enabled tools. Our experiments reveal that indirect prompts with injected malicious font can bypass LLM safety mechanisms through external resources, achieving varying success rates based on data sensitivity and prompt design. Our research underscores the urgent need for enhanced security measures in LLM deployments when processing external content.

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Layer-Level Self-Exposure and Patch: Affirmative Token Mitigation for Jailbreak Attack Defense
Yang Ouyang | Hengrui Gu | Shuhang Lin | Wenyue Hua | Jie Peng | Bhavya Kailkhura | Meijun Gao | Tianlong Chen | Kaixiong Zhou
Proceedings of the 2025 Conference of the Nations of the Americas Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 1: Long Papers)

As large language models (LLMs) are increasingly deployed in diverse applications, including chatbot assistants and code generation, aligning their behavior with safety and ethical standards has become paramount. However, jailbreak attacks, which exploit vulnerabilities to elicit unintended or harmful outputs, threaten LLMs safety significantly. In this paper, we introduce Layer-AdvPatcher, a novel methodology designed to defend against jailbreak attacks by utilizing an unlearning strategy to patch specific layers within LLMs through self-augmented datasets. Our insight is that certain layer(s), tend to produce affirmative tokens when faced with harmful prompts. By identifying these layers and adversarially exposing them to generate more harmful data, one can understand their inherent and diverse vulnerabilities to attacks. With these exposures, we then “unlearn” these issues, reducing the impact of affirmative tokens and hence minimizing jailbreak risks while keeping the model’s responses to safe queries intact.We conduct extensive experiments on two models, four benchmark datasets, and multiple state-of-the-art jailbreak attacks to demonstrate the efficacy of our approach. Results indicate that our framework reduces the harmfulness and attack success rate of jailbreak attacks without compromising utility for benign queries compared to recent defense methods. Our code is publicly available at: https://github.com/oyy2000/LayerAdvPatcher

2024

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BattleAgent: Multi-modal Dynamic Emulation on Historical Battles to Complement Historical Analysis
Shuhang Lin | Wenyue Hua | Lingyao Li | Che-Jui Chang | Lizhou Fan | Jianchao Ji | Hang Hua | Mingyu Jin | Jiebo Luo | Yongfeng Zhang
Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing: System Demonstrations

This paper presents BattleAgent, a detailed emulation demonstration system that combines the Large Vision-Language Model (VLM) and Multi-Agent System (MAS). This novel system aims to emulate complex dynamic interactions among multiple agents, as well as between agents and their environments, over a period of time. The emulation showcases the current capabilities of agents, featuring fine-grained multi-modal interactions between agents and landscapes. It develops customizable agent structures to meet specific situational requirements, for example, a variety of battle-related activities like scouting and trench digging. These components collaborate to recreate historical events in a lively and comprehensive manner. This methodology holds the potential to substantially improve visualization of historical events and deepen our understanding of historical events especially from the perspective of decision making. The data and code for this project are accessible at https://github.com/agiresearch/battleagent and the demo is accessible at https://drive.google.com/file/d/1I5B3KWiYCSSP1uMiPGNmXlTmild-MzRJ/view?usp=sharing.