mlsanityData to 7 Oct 2026

RefineRAG: Word-Level Poisoning Attacks via Retriever-Guided Text Refinement

arXiv 2604.07403 ↗First posted 8 Apr 2026cs.CRcited by 0

On the map: Retrieval-augmented generation → Privacy and security of RAG

Abstract (arXiv)

Retrieval-Augmented Generation (RAG) significantly enhances Large Language Models (LLMs), but simultaneously exposes a critical vulnerability to knowledge poisoning attacks. Existing attack methods like PoisonedRAG remain detectable due to coarse-grained separate-and-concatenate strategies. To bridge this gap, we propose RefineRAG, a novel framework that treats poisoning as a holistic word-level refinement problem. It operates in two stages: Macro Generation produces toxic seeds guaranteed to induce target answers, while Micro Refinement employs a retriever-in-the-loop optimization to maximize retrieval priority without compromising naturalness. Evaluations on NQ and MSMARCO demonstrate that RefineRAG achieves state-of-the-art effectiveness, securing a 90% Attack Success Rate on NQ, while registering the lowest grammar errors and repetition rates among all baselines. Crucially, our proxy-optimized attacks successfully transfer to black-box victim systems, highlighting a severe practical threat.

Key facts. No citing papers in the map yet (data through 7 Oct 2026). Placed in Privacy and security of RAG, one of 15 directions in Retrieval-augmented generation. Builds on 18 of its 27 references that are in the map. First posted on arXiv 8 Apr 2026.

Builds on

18 of 27 references.

Closest ancestors · 2

Same direction, newest first

  1. 2025CPA-RAG:Covert Poisoning Attacks on Retrieval-Augmented Generation in Large Language Models26 May
  2. 2024PoisonedRAG: Knowledge Corruption Attacks to Retrieval-Augmented Generation of Large Language Models12 Feb

Other references · 16

  1. 2018BERT: Pre-training of Deep Bidirectional Transformers for Language Understandingcited by 40,204
  2. 2023Llama 2: Open Foundation and Fine-Tuned Chat Modelscited by 12,865
  3. 2020Retrieval-Augmented Generation for Knowledge-Intensive NLP Taskscited by 9,160
  4. 2023Jailbroken: How Does LLM Safety Training Fail?cited by 1,565
  5. 2024From Local to Global: A Graph RAG Approach to Query-Focused Summarizationcited by 1,411
  6. 2021Unsupervised Dense Information Retrieval with Contrastive Learningcited by 1,203
  7. 2020Approximate Nearest Neighbor Negative Contrastive Learning for Dense Text Retrievalcited by 846
  8. 2022Ignore Previous Prompt: Attack Techniques For Language Modelscited by 760
  9. 2019Is BERT Really Robust? A Strong Baseline for Natural Language Attack on Text Classification and Entailmentcited by 663
  10. 2020BERT-ATTACK: Adversarial Attack Against BERT Using BERTcited by 488
  11. 2023Catastrophic Jailbreak of Open-source LLMs via Exploiting Generationcited by 439
  12. 2023Benchmarking Large Language Models in Retrieval-Augmented Generationcited by 307
4 more
  1. 2024Evaluating Retrieval Quality in Retrieval-Augmented Generationcited by 90
  2. 2024Financial Report Chunking for Effective Retrieval Augmented Generationcited by 46
  3. 2023QASiNa: Religious Domain Question Answering using Sirah Nabawiyahcited by 14
  4. 2024MeTMaP: Metamorphic Testing for Detecting False Vector Matching Problems in LLM Augmented Generationcited by 4

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  1. 2025Practical Poisoning Attacks against Retrieval-Augmented Generation
  2. 2025Uncovering Competing Poisoning Attacks in Retrieval-Augmented Generation
  3. 2025Benchmarking Poisoning Attacks against Retrieval-Augmented Generation
  4. 2026Semantic Chameleon: Corpus-Dependent Poisoning Attacks and Defenses in RAG Systems
  5. 2025One Shot Dominance: Knowledge Poisoning Attack on Retrieval-Augmented Generation Systems
  6. 2026When Poison Fails After Retrieval: Revisiting Corpus Poisoning under Chunking and Reranking Pipelines
  7. 2026Confundo: Learning to Generate Robust Poison for Practical RAG Systems
  8. 2025DisarmRAG: Stealthy Retriever-Centric Poisoning to Disable Self-Correction in Retrieval-Augmented Generation (Extended Version)