GR-SAP: Generative Replay for Safety Alignment Preservation during Fine-Tuning

Zhouxiang Fang, Jiawei Zhou, Hanjie Chen


Abstract
Recent studies show that the safety alignment of large language models (LLMs) can be easily compromised even by seemingly non-adversarial fine-tuning. To preserve safety alignment during fine-tuning, a widely used strategy is to jointly optimize safety and task objectives by mixing in the original alignment data, which is typically inaccessible even for open-weight LLMs. Inspired by generative replay in continual learning, we propose Generative Replay for Safety Alignment Preservation (GR-SAP), a unified framework that synthesizes domain-specific alignment data from LLMs and integrate them during downstream adaptation to preserve safety alignment. Theoretical and empirical analyses demonstrate this synthetic data serves as a reliable proxy for the original alignment data. Experiments across various models and downstream tasks show that GR-SAP substantially mitigates fine-tuning–induced safety degradation while maintaining comparable downstream performance.
Anthology ID:
2026.emnlp-main.50
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
Note:
Pages:
1131–1153
Language:
URL:
https://aclanthology.org/2026.emnlp-main.50/
DOI:
Bibkey:
Cite (ACL):
Zhouxiang Fang, Jiawei Zhou, and Hanjie Chen. 2026. GR-SAP: Generative Replay for Safety Alignment Preservation during Fine-Tuning. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 1131–1153, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
GR-SAP: Generative Replay for Safety Alignment Preservation during Fine-Tuning (Fang et al., EMNLP 2026)
Copy Citation:
PDF:
https://aclanthology.org/2026.emnlp-main.50.pdf