Asymmetric Relational-Geometry Driven Universal Adversarial Perturbations for Vision-Language Models

Jiaxin Ye, Weihai Li, Ying Wang, Simeng Qin, Zhitao Zeng, Zikai Xu


Abstract
Although vision-language pre-trained (VLP) models have achieved remarkable success across multimodal tasks, they remain vulnerable to adversarial perturbations.Existing universal adversarial perturbation (UAP) methods in multimodal settings—whether generator-based or optimization-based—often suffer from limited cross-model transferability, especially in black-box scenarios.We attribute this limitation to the prevalent use of symmetric or distribution-level objectives that overlook the asymmetric roles of image and text modalities and the relational nature of vision-language representations.To address this issue, we propose ARG-Attack, an optimization-based framework that learns universal perturbations under an asymmetric relational-geometry driven objective.Our method integrates three complementary components: a cosine-based loss that induces directional semantic drift in visual features, a center shift loss that geometrically regularizes adversarial embeddings toward a shared semantic center, and a relational polarity loss that explicitly disrupts image–text matching relationships.Together, these objectives enable effective cross-modal interaction without relying on model-specific training losses or probabilistic distribution matching.In addition, we adopt an adaptive gradient update strategy inspired by Adam optimization to stabilize training and accelerate convergence.Extensive experiments across multiple vision-language models and tasks demonstrate that ARG-Attack achieves competitive white-box performance and significantly outperforms state-of-the-art methods in black-box transfer settings.
Anthology ID:
2026.findings-acl.393
Volume:
Findings of the Association for Computational Linguistics: ACL 2026
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
Venue:
Findings
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Publisher:
Association for Computational Linguistics
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Pages:
7997–8014
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https://preview.aclanthology.org/ingest-acl/2026.findings-acl.393/
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Cite (ACL):
Jiaxin Ye, Weihai Li, Ying Wang, Simeng Qin, Zhitao Zeng, and Zikai Xu. 2026. Asymmetric Relational-Geometry Driven Universal Adversarial Perturbations for Vision-Language Models. In Findings of the Association for Computational Linguistics: ACL 2026, pages 7997–8014, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
Asymmetric Relational-Geometry Driven Universal Adversarial Perturbations for Vision-Language Models (Ye et al., Findings 2026)
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https://preview.aclanthology.org/ingest-acl/2026.findings-acl.393.pdf
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