From Shallow Alignment to Source Correction: Robust Safety Alignment for LLMs

Guan Wang, Xuehai Tang, Biyu Zhou, Jizhong Han, Songlin Hu


Abstract
Persistent vulnerabilities in safety alignment hinder the deployment of large language models (LLMs). Existing methods remain susceptible to jailbreak attacks, suggesting a fundamental, unaddressed flaw in current safety paradigms. In this work, we diagnose the root cause of this fragility, identifying a systemic issue we term Depth-wise Alignment Discrepancy. We find a fundamental misalignment: harmful vectors—latent representations predisposed to unsafe content—predominantly originate in the model’s lower layers, yet conventional alignment training concentrates its corrective gradients disproportionately on the top-most layers. This creates a brittle, "end-of-pipe" defense that is easily bypassed. To address this discrepancy, we propose SAGA, a framework that achieves robust safety through two synergistic innovations. First, it leverages high-entropy safety data, constructed via an iterative entropy ascent procedure, to provide the deep semantic signals necessary to reach the source of harmfulness. Second, it introduces a novel Synergistic Gradient Scaling (SGS) mechanism to explicitly reshape the gradient flow, ensuring these corrective signals are precisely applied to the identified vulnerable layers. Extensive experiments on five LLMs against six distinct jailbreak attacks demonstrate SAGA’s superiority, reducing attack success rates (ASR) by 21%–63% compared to state-of-the-art baselines. Our method preserves downstream task accuracy while introducing minimal computational overhead (<3%).
Anthology ID:
2026.emnlp-main.2557
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:
58116–58137
Language:
URL:
https://aclanthology.org/2026.emnlp-main.2557/
DOI:
Bibkey:
Cite (ACL):
Guan Wang, Xuehai Tang, Biyu Zhou, Jizhong Han, and Songlin Hu. 2026. From Shallow Alignment to Source Correction: Robust Safety Alignment for LLMs. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 58116–58137, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
From Shallow Alignment to Source Correction: Robust Safety Alignment for LLMs (Wang et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.2557.pdf