Saved in:
Bibliographic Details
Main Authors: Zhang, Ci, Ding, Zhaojun, Yang, Chence, Liu, Jun, Zhai, Xiaoming, Huang, Shaoyi, Li, Beiwen, Ma, Xiaolong, Lu, Jin, Yuan, Geng
Format: Preprint
Published: 2026
Subjects:
Online Access:https://arxiv.org/abs/2603.06640
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866910044795174912
author Zhang, Ci
Ding, Zhaojun
Yang, Chence
Liu, Jun
Zhai, Xiaoming
Huang, Shaoyi
Li, Beiwen
Ma, Xiaolong
Lu, Jin
Yuan, Geng
author_facet Zhang, Ci
Ding, Zhaojun
Yang, Chence
Liu, Jun
Zhai, Xiaoming
Huang, Shaoyi
Li, Beiwen
Ma, Xiaolong
Lu, Jin
Yuan, Geng
contents Pruning-based unlearning has recently emerged as a fast, training-free, and data-independent approach to remove undesired concepts from diffusion models. It promises high efficiency and robustness, offering an attractive alternative to traditional fine-tuning or editing-based unlearning. However, in this paper we uncover a hidden danger behind this promising paradigm. We find that the locations of pruned weights, typically set to zero during unlearning, can act as side-channel signals that leak critical information about the erased concepts. To verify this vulnerability, we design a novel attack framework capable of reviving erased concepts from pruned diffusion models in a fully data-free and training-free manner. Our experiments confirm that pruning-based unlearning is not inherently secure, as erased concepts can be effectively revived without any additional data or retraining. Extensive experiments on diffusion-based unlearning based on concept related weights lead to the conclusion: once the critical concept-related weights in diffusion models are identified, our method can effectively recover the original concept regardless of how the weights are manipulated. Finally, we explore potential defense strategies and advocate safer pruning mechanisms that conceal pruning locations while preserving unlearning effectiveness, providing practical insights for designing more secure pruning-based unlearning frameworks.
format Preprint
id arxiv_https___arxiv_org_abs_2603_06640
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Roots Beneath the Cut: Uncovering the Risk of Concept Revival in Pruning-Based Unlearning for Diffusion Models
Zhang, Ci
Ding, Zhaojun
Yang, Chence
Liu, Jun
Zhai, Xiaoming
Huang, Shaoyi
Li, Beiwen
Ma, Xiaolong
Lu, Jin
Yuan, Geng
Computer Vision and Pattern Recognition
Machine Learning
Pruning-based unlearning has recently emerged as a fast, training-free, and data-independent approach to remove undesired concepts from diffusion models. It promises high efficiency and robustness, offering an attractive alternative to traditional fine-tuning or editing-based unlearning. However, in this paper we uncover a hidden danger behind this promising paradigm. We find that the locations of pruned weights, typically set to zero during unlearning, can act as side-channel signals that leak critical information about the erased concepts. To verify this vulnerability, we design a novel attack framework capable of reviving erased concepts from pruned diffusion models in a fully data-free and training-free manner. Our experiments confirm that pruning-based unlearning is not inherently secure, as erased concepts can be effectively revived without any additional data or retraining. Extensive experiments on diffusion-based unlearning based on concept related weights lead to the conclusion: once the critical concept-related weights in diffusion models are identified, our method can effectively recover the original concept regardless of how the weights are manipulated. Finally, we explore potential defense strategies and advocate safer pruning mechanisms that conceal pruning locations while preserving unlearning effectiveness, providing practical insights for designing more secure pruning-based unlearning frameworks.
title Roots Beneath the Cut: Uncovering the Risk of Concept Revival in Pruning-Based Unlearning for Diffusion Models
topic Computer Vision and Pattern Recognition
Machine Learning
url https://arxiv.org/abs/2603.06640