Junyu Wang · PhD Researcher

Security research for a web shaped by intelligent agents.

I study the security of AI agents, language models, and the web— measuring where intelligent systems fail and translating those failures into stronger defenses.

Computer Science · Missouri University of Science and Technology

Portrait of Junyu Wang
PhD student, Computer ScienceMissouri S&T · 2025—present
Research portfolio

Research archive.

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USENIX Security ’26 Accepted

COGNITION: From Evaluation to Defense against Multimodal LLM CAPTCHA Solvers

Junyu Wang, Changjia Zhu, Yuanbo Zhou, Lingyao Li, Xu He, Mingkui Wei, Junjie Xiong

COGNITION maps the practical boundary of automated visual CAPTCHA solving and turns that evidence into concrete redesign guidance. The study pairs broad evaluation with a defense case study that reduces state-of-the-art solver success from over 95% to 0%.

Web securityMultimodal LLMsCAPTCHA robustness

Three connected security boundaries.

My work follows the points where model capability, autonomous action, and web infrastructure meet.

01

Agentic System Security

How autonomous systems expand trust boundaries, accumulate state, and create new failure modes.

02

LLM Security

Evaluating model behavior under adversarial prompts, tools, memory, and multimodal inputs.

03

Web Security

Designing robust defenses for interfaces where people, agents, and automated services meet.

Building security evidence that can change design.

I am a PhD student in Computer Science at Missouri S&T. My research examines agentic system security, LLM security, web security, and the practical boundary between evaluation and defense.

I received a B.Eng. in Data Science and Big Data Technology from the University of Shanghai for Science and Technology and previously worked on data strategy systems at Fast Retailing (China).

Current
Ph.D. in Computer Science, 2025—present
Education
B.Eng. in Data Science and Big Data Technology, 2021—2025