VulAgent: Hypothesis-Validation Driven Multi-Agent Architecture for Vulnerability Detection

Ziliang Wang, Ge Li, Jia Li, Hao Zhu, Zhi Jin


Abstract
Vulnerability detection with language models is challenging: it requires (i) precisely localizing security-sensitive code and (ii) reasoning about potential vulnerability conditions under complex, partially observed program context. We present VulAgent, a multi-agent vulnerability detection framework based on hypothesis validation. Our design is inspired by how human auditors review code: when noticing a sensitive operation, they form a hypothesis about a possible vulnerability, consider potential trigger paths, and then verify the hypothesis against the project context. Given a code unit, VulAgent first applies multi-view analyzers to identify and localize security-sensitive operations from complementary perspectives. For each sensitive operation, it then constructs an explicit vulnerability hypothesis—including triggering (or exploitation) preconditions and a candidate trigger path—and validates the hypothesis using project context together with the model’s general knowledge of commonly used APIs and security patterns. This validation-oriented design reduces speculative reports and substantially lowers false positives. Across PrimeVul and SVEN, VulAgent improves accuracy by 6.6 percentage points on average, increases vulnerable–fixed pair identification by up to 4.5x (2.46x on average), and reduces false positive rate by 36% relative to recent LLM-based baselines.
Anthology ID:
2026.findings-acl.928
Volume:
Findings of the Association for Computational Linguistics: ACL 2026
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
Venue:
Findings
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Publisher:
Association for Computational Linguistics
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Pages:
18598–18616
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URL:
https://preview.aclanthology.org/ingest-acl/2026.findings-acl.928/
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Cite (ACL):
Ziliang Wang, Ge Li, Jia Li, Hao Zhu, and Zhi Jin. 2026. VulAgent: Hypothesis-Validation Driven Multi-Agent Architecture for Vulnerability Detection. In Findings of the Association for Computational Linguistics: ACL 2026, pages 18598–18616, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
VulAgent: Hypothesis-Validation Driven Multi-Agent Architecture for Vulnerability Detection (Wang et al., Findings 2026)
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https://preview.aclanthology.org/ingest-acl/2026.findings-acl.928.pdf
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