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arXiv · 2501.16902

Document Screenshot Retrievers are Vulnerable to Pixel Poisoning Attacks

Shengyao Zhuang·Ekaterina Khramtsova·Xueguang Ma·Bevan Koopman·Jimmy Lin·Guido Zuccon
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Abstract

Recent advancements in dense retrieval have introduced vision-language model (VLM)-based retrievers, such as DSE and ColPali, which leverage document screenshots embedded as vectors to enable effective search and offer a simplified pipeline over traditional text-only methods. In this study, we propose three pixel poisoning attack methods designed to compromise VLM-based retrievers and evaluate their effectiveness under various attack settings and parameter configurations. Our empirical results demonstrate that injecting even a single adversarial screenshot into the retrieval corpus can significantly disrupt search results, poisoning the top-10 retrieved documents for 41.9% of queries in the case of DSE and 26.4% for ColPali. These vulnerability rates notably exceed those observed with equivalent attacks on text-only retrievers. Moreover, when targeting a small set of known queries, the attack success rate raises, achieving complete success in certain cases. By exposing the vulnerabilities inherent in vision-language models, this work highlights the potential risks associated with their deployment.

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Shengyao Zhuang, Ekaterina Khramtsova, Xueguang Ma, Bevan Koopman, Jimmy Lin, Guido Zuccon. 2025-01-28. Document Screenshot Retrievers are Vulnerable to Pixel Poisoning Attacks. https://arxiv.org/abs/2501.16902

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