KEPo: Knowledge Evolution Poison on Graph-based Retrieval-Augmented Generation

Fuente: arXiv
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Main Authors: Chen, Qizhi, Qi, Chao, Huang, Yihong, Li, Muquan, Wang, Rongzheng, Zhang, Dongyang, Qin, Ke, Liang, Shuang
Format: Preprint
Published: 2026
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_version_ 1866914392387354624
author Chen, Qizhi
Qi, Chao
Huang, Yihong
Li, Muquan
Wang, Rongzheng
Zhang, Dongyang
Qin, Ke
Liang, Shuang
author_facet Chen, Qizhi
Qi, Chao
Huang, Yihong
Li, Muquan
Wang, Rongzheng
Zhang, Dongyang
Qin, Ke
Liang, Shuang
contents Graph-based Retrieval-Augmented Generation (GraphRAG) constructs the Knowledge Graph (KG) from external databases to enhance the timeliness and accuracy of Large Language Model (LLM) generations. However, this reliance on external data introduces new attack surfaces. Attackers can inject poisoned texts into databases to manipulate LLMs into producing harmful target responses for attacker-chosen queries. Existing research primarily focuses on attacking conventional RAG systems. However, such methods are ineffective against GraphRAG. This robustness derives from the KG abstraction of GraphRAG, which reorganizes injected text into a graph before retrieval, thereby enabling the LLM to reason based on the restructured context instead of raw poisoned passages. To expose latent security vulnerabilities in GraphRAG, we propose Knowledge Evolution Poison (KEPo), a novel poisoning attack method specifically designed for GraphRAG. For each target query, KEPo first generates a toxic event containing poisoned knowledge based on the target answer. By fabricating event backgrounds and forging knowledge evolution paths from original facts to the toxic event, it then poisons the KG and misleads the LLM into treating the poisoned knowledge as the final result. In multi-target attack scenarios, KEPo further connects multiple attack corpora, enabling their poisoned knowledge to mutually reinforce while expanding the scale of poisoned communities, thereby amplifying attack effectiveness. Experimental results across multiple datasets demonstrate that KEPo achieves state-of-the-art attack success rates for both single-target and multi-target attacks, significantly outperforming previous methods.
format Preprint
id arxiv_https___arxiv_org_abs_2603_11501
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle KEPo: Knowledge Evolution Poison on Graph-based Retrieval-Augmented Generation
Chen, Qizhi
Qi, Chao
Huang, Yihong
Li, Muquan
Wang, Rongzheng
Zhang, Dongyang
Qin, Ke
Liang, Shuang
Machine Learning
Artificial Intelligence
Cryptography and Security
Graph-based Retrieval-Augmented Generation (GraphRAG) constructs the Knowledge Graph (KG) from external databases to enhance the timeliness and accuracy of Large Language Model (LLM) generations. However, this reliance on external data introduces new attack surfaces. Attackers can inject poisoned texts into databases to manipulate LLMs into producing harmful target responses for attacker-chosen queries. Existing research primarily focuses on attacking conventional RAG systems. However, such methods are ineffective against GraphRAG. This robustness derives from the KG abstraction of GraphRAG, which reorganizes injected text into a graph before retrieval, thereby enabling the LLM to reason based on the restructured context instead of raw poisoned passages. To expose latent security vulnerabilities in GraphRAG, we propose Knowledge Evolution Poison (KEPo), a novel poisoning attack method specifically designed for GraphRAG. For each target query, KEPo first generates a toxic event containing poisoned knowledge based on the target answer. By fabricating event backgrounds and forging knowledge evolution paths from original facts to the toxic event, it then poisons the KG and misleads the LLM into treating the poisoned knowledge as the final result. In multi-target attack scenarios, KEPo further connects multiple attack corpora, enabling their poisoned knowledge to mutually reinforce while expanding the scale of poisoned communities, thereby amplifying attack effectiveness. Experimental results across multiple datasets demonstrate that KEPo achieves state-of-the-art attack success rates for both single-target and multi-target attacks, significantly outperforming previous methods.
title KEPo: Knowledge Evolution Poison on Graph-based Retrieval-Augmented Generation
topic Machine Learning
Artificial Intelligence
Cryptography and Security
url https://arxiv.org/abs/2603.11501