PRISM: Multidimensional Safety Risk Detection and Measurement Beyond Superficial Compliance for LLMs

YIfan Sun, Xiang Zhao, Beining Lin, Feng Huang, You Song


Abstract
Existing LLM safety measures operate as black boxes, lacking categorical precision and calibrated severity assessment. We propose **PRISM** (**P**rototypical **R**epresentation for **I**nternal **S**afety **M**apping), a fine-grained two-stage safety auditing framework grounded in internal mechanistic representations. Stage I localizes functional safety zones via spectral analysis and maps internal activations onto concept prototypes for camouflage-resilient categorical risk identification. Stage II decomposes violation severity across orthogonal dimensions through structured CoT reasoning, producing calibrated human-auditable ordinal verdicts. PRISM achieves a new best F1 of 77.60% on the adversarial ToxicChat benchmark and approaches 671B frontier judges within a 2.3% margin on severity calibration, demonstrating that mechanistic grounding and principled task formulation can substitute for scale in fine-grained safety governance.
Anthology ID:
2026.findings-emnlp.1627
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
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SIGDAT
Publisher:
Association for Computational Linguistics
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Pages:
34612–34632
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.1627/
DOI:
Bibkey:
Cite (ACL):
YIfan Sun, Xiang Zhao, Beining Lin, Feng Huang, and You Song. 2026. PRISM: Multidimensional Safety Risk Detection and Measurement Beyond Superficial Compliance for LLMs. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 34612–34632, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
PRISM: Multidimensional Safety Risk Detection and Measurement Beyond Superficial Compliance for LLMs (Sun et al., Findings 2026)
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https://aclanthology.org/2026.findings-emnlp.1627.pdf