@inproceedings{huang-etal-2026-coda-mitigating,
title = "{CODA}: Mitigating Over-Refusal and Jailbreaks in Large Language Models via Codebook-Orthogonal Direction Alignment",
author = "Huang, Feng and
Zhang, Yunqi and
Huang, Qiang and
Yu, Qing and
Huang, Yongfeng",
editor = "Lee, Hung-Yi and
Dev, Sunipa and
Li, Jessy and
Elliott, Desmond",
booktitle = "Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing",
month = oct,
year = "2026",
address = "Budapest, Hungary",
publisher = "Association for Computational Linguistics",
url = "https://aclanthology.org/2026.emnlp-main.1243/",
pages = "28326--28348",
ISBN = "979-8-89176-459-0",
abstract = "Safety alignment plays a vital role in ensuring the reliability of Large Language Models (LLMs) by mitigating risks from malicious queries. To avoid the high computational costs of post-training, recent research has increasingly shifted toward inference-time alignment via continuous activation steering.\par However, the geometric entanglement of harmful and benign technical representations within these continuous spaces impedes precise calibration, inevitably trapping models in a severe dilemma between jailbreak vulnerability and benign over-refusal. To address this, we propose Codebook-Orthogonal Direction Alignment (CODA), an inference-time framework that projects hidden states onto a vector-quantized codebook to serve as a discrete control interface.\par Specifically, to break continuous directional entanglement, CODA estimates steering directions over discrete codebook anchors. To eliminate the geometric interference triggering over-refusals, CODA softly orthogonalizes the safety direction with respect to benign technical intent.\par Finally, to prevent rigid over-correction, CODA forwards the decoupled vectors to yield dynamically adjusted steering strengths during generation via risk gating and exponential time decay. Experiments across a diverse set of open-weight LLMs demonstrate that CODA consistently yields a stronger safety{--}utility trade-off than continuous steering baselines, indicating that discrete representations provide a more effective mechanism for disentangling safety from utility."
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<abstract>Safety alignment plays a vital role in ensuring the reliability of Large Language Models (LLMs) by mitigating risks from malicious queries. To avoid the high computational costs of post-training, recent research has increasingly shifted toward inference-time alignment via continuous activation steering.\par However, the geometric entanglement of harmful and benign technical representations within these continuous spaces impedes precise calibration, inevitably trapping models in a severe dilemma between jailbreak vulnerability and benign over-refusal. To address this, we propose Codebook-Orthogonal Direction Alignment (CODA), an inference-time framework that projects hidden states onto a vector-quantized codebook to serve as a discrete control interface.\par Specifically, to break continuous directional entanglement, CODA estimates steering directions over discrete codebook anchors. To eliminate the geometric interference triggering over-refusals, CODA softly orthogonalizes the safety direction with respect to benign technical intent.\par Finally, to prevent rigid over-correction, CODA forwards the decoupled vectors to yield dynamically adjusted steering strengths during generation via risk gating and exponential time decay. Experiments across a diverse set of open-weight LLMs demonstrate that CODA consistently yields a stronger safety–utility trade-off than continuous steering baselines, indicating that discrete representations provide a more effective mechanism for disentangling safety from utility.</abstract>
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%0 Conference Proceedings
%T CODA: Mitigating Over-Refusal and Jailbreaks in Large Language Models via Codebook-Orthogonal Direction Alignment
%A Huang, Feng
%A Zhang, Yunqi
%A Huang, Qiang
%A Yu, Qing
%A Huang, Yongfeng
%Y Lee, Hung-Yi
%Y Dev, Sunipa
%Y Li, Jessy
%Y Elliott, Desmond
%S Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
%D 2026
%8 October
%I Association for Computational Linguistics
%C Budapest, Hungary
%@ 979-8-89176-459-0
%F huang-etal-2026-coda-mitigating
%X Safety alignment plays a vital role in ensuring the reliability of Large Language Models (LLMs) by mitigating risks from malicious queries. To avoid the high computational costs of post-training, recent research has increasingly shifted toward inference-time alignment via continuous activation steering.\par However, the geometric entanglement of harmful and benign technical representations within these continuous spaces impedes precise calibration, inevitably trapping models in a severe dilemma between jailbreak vulnerability and benign over-refusal. To address this, we propose Codebook-Orthogonal Direction Alignment (CODA), an inference-time framework that projects hidden states onto a vector-quantized codebook to serve as a discrete control interface.\par Specifically, to break continuous directional entanglement, CODA estimates steering directions over discrete codebook anchors. To eliminate the geometric interference triggering over-refusals, CODA softly orthogonalizes the safety direction with respect to benign technical intent.\par Finally, to prevent rigid over-correction, CODA forwards the decoupled vectors to yield dynamically adjusted steering strengths during generation via risk gating and exponential time decay. Experiments across a diverse set of open-weight LLMs demonstrate that CODA consistently yields a stronger safety–utility trade-off than continuous steering baselines, indicating that discrete representations provide a more effective mechanism for disentangling safety from utility.
%U https://aclanthology.org/2026.emnlp-main.1243/
%P 28326-28348
Markdown (Informal)
[CODA: Mitigating Over-Refusal and Jailbreaks in Large Language Models via Codebook-Orthogonal Direction Alignment](https://aclanthology.org/2026.emnlp-main.1243/) (Huang et al., EMNLP 2026)
ACL