CoRRSafe: Improving LRM Safety via Co-optimized Fine-Grained Reasoning and Response Alignment

Yangxiao Song, Bing Xu, Bufan Xu, Muyun Yang, Conghui Zhu, Huanqin Wu, Bojie Hu, Hongjiao Guan, Wenpeng Lu


Abstract
Large reasoning models (LRMs) with explicit Chain-of-Thought (CoT) face significant safety risks, where unsafe content may appear in intermediate reasoning even when the final response is safe. Existing safety alignment methods often ignore the safety of the reasoning and frequently suffer from over-alignment issues. To address these, we propose CoRRSafe (Co-optimized Reasoning and Response Safe), a two-stage framework designed to comprehensively enhance LRM safety while balancing safety and over-refusal. The method begins with a response cold-start stage using filtered high-quality data for initial alignment on responses. Then we implement a GRPO-based training strategy with fine-grained rewards to jointly evaluate segmented reasoning steps and final answers. This approach effectively guides the model to autonomously learn safe reasoning and response behaviors. Experiments on multiple LRMs show that CoRRSafe achieves state of the art performance in reasoning safety and achieves the best trade-off between safety and false refusal. On DeepSeek-Distill-R1-8B, it raises the Reasoning Safety Rate from 16.86% to 89.31% and reduces the Attack Success Rate from 78.74% to 4.06%, with only a 16.56% increase in false refusal. Further analysis confirms that co-optimizing reasoning and response is essential, as optimizing either alone fails to overcome safety performance ceilings.
Anthology ID:
2026.emnlp-main.1217
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
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Pages:
27790–27814
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URL:
https://aclanthology.org/2026.emnlp-main.1217/
DOI:
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Cite (ACL):
Yangxiao Song, Bing Xu, Bufan Xu, Muyun Yang, Conghui Zhu, Huanqin Wu, Bojie Hu, Hongjiao Guan, and Wenpeng Lu. 2026. CoRRSafe: Improving LRM Safety via Co-optimized Fine-Grained Reasoning and Response Alignment. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 27790–27814, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
CoRRSafe: Improving LRM Safety via Co-optimized Fine-Grained Reasoning and Response Alignment (Song et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.1217.pdf