Role-Conditioned Refusals: Evaluating Access Control Reasoning in Large Language Models

Đorđe Klisura, Joseph Khoury, Ashish Kundu, Ram Krishnan, Anthony Rios


Abstract
Access control is a cornerstone of secure computing, yet large language models often blur role boundaries by producing unrestricted responses. We study role-conditioned refusals, focusing on the LLM’s ability to adhere to access control policies by answering when authorized and refusing when not. To evaluate this behavior, we created a novel dataset that extends the Spider and BIRD text-to-SQL datasets, both of which have been modified with realistic PostgreSQL role-based policies at the table and column levels. We compare three designs: (i) zero or few-shot prompting, (ii) a two-step generator-verifier pipeline that checks SQL against policy, and (iii) LoRA fine-tuned models that learn permission awareness directly. Across multiple model families, explicit verification (the two-step framework) improves refusal precision and lowers false permits. At the same time, fine-tuning achieves a stronger balance between safety and utility (i.e., when considering execution accuracy). Longer and more complex policies consistently reduce the reliability of all systems. We release RBAC-augmented datasets and code.
Anthology ID:
2026.findings-eacl.316
Volume:
Findings of the Association for Computational Linguistics: EACL 2026
Month:
March
Year:
2026
Address:
Rabat, Morocco
Editors:
Vera Demberg, Kentaro Inui, Lluís Marquez
Venue:
Findings
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Publisher:
Association for Computational Linguistics
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Pages:
6018–6034
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https://preview.aclanthology.org/ingest-eacl/2026.findings-eacl.316/
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Cite (ACL):
Đorđe Klisura, Joseph Khoury, Ashish Kundu, Ram Krishnan, and Anthony Rios. 2026. Role-Conditioned Refusals: Evaluating Access Control Reasoning in Large Language Models. In Findings of the Association for Computational Linguistics: EACL 2026, pages 6018–6034, Rabat, Morocco. Association for Computational Linguistics.
Cite (Informal):
Role-Conditioned Refusals: Evaluating Access Control Reasoning in Large Language Models (Klisura et al., Findings 2026)
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