Beyond Language Priors: Diagnosing and Fixing Visual-Origin Hallucinations in Multimodal LLM
On the map: Multimodal LLMs / vision-language models → Hallucination mitigation in LVLMs
Abstract (arXiv)
Existing research on object hallucination in multimodal large language models (MLLMs) predominantly attributes the problem to language priors such as over-reliance on textual co-occurrence statistics. We challenge this view by presenting quantitative evidence for a complementary, under-explored cause: visual-origin hallucination, where hallucinations arise from incorrect visual feature extraction and misalignment between image and text embeddings. Through cosine similarity analysis and Smooth Grad-CAM entropy measurements, we show that hallucinated samples exhibit systematically lower image-text similarity (average 0.158 vs. -0.122) and inverted attention patterns, where attention is dispersed when the target object is present but wrongly concentrated when it is absent. Guided by this diagnosis, we propose Adversarial Contrastive Fine-Tuning (ACFT). ACFT uses an Adversarial Hallucination Attribute Flipping (AHAF) procedure, involving minimal, targeted adversarial perturbations that flip an image's hallucination attribute, to construct perfectly aligned positive-negative pairs, which are then used for contrastive fine-tuning. AHAF simultaneously serves as a diagnostic probe, revealing that MLLM visual representations lie dangerously close to hallucination decision boundaries. Requiring only 0.9% of the COCO dataset and adding zero inference overhead, ACFT achieves state-of-the-art performance on POPE, MME, and four description-level hallucination benchmarks across LLaVA, MiniGPT-4, and Qwen2.5-VL. Code is available at https://github.com/zxp555/ACFT_MM
Key facts. No citing papers in the map yet (data through 7 Oct 2026). Placed in Hallucination mitigation in LVLMs, one of 16 directions in Multimodal LLMs / vision-language models. Builds on 21 of its 33 references that are in the map. First posted on arXiv 31 Aug 2026.
Builds on
21 of 33 references.
Closest ancestors · 8
Same direction, newest first
- 2025PerturboLLaVA: Reducing Multimodal Hallucinations with Perturbative Visual Training9 Mar
- 2025Mitigating Hallucinations in Large Vision-Language Models via DPO: On-Policy Data Hold the Key16 Jan
- 2024Reducing Hallucinations in Vision-Language Models via Latent Space Steering21 Oct
- 2024IBD: Alleviating Hallucinations in Large Vision-Language Models via Image-Biased Decoding28 Feb
- 2023OPERA: Alleviating Hallucination in Multi-Modal Large Language Models via Over-Trust Penalty and Retrospection-Allocation29 Nov
- 2023Mitigating Object Hallucinations in Large Vision-Language Models through Visual Contrastive Decoding28 Nov
- 2023Analyzing and Mitigating Object Hallucination in Large Vision-Language Models1 Oct
- 2023Evaluating Object Hallucination in Large Vision-Language Models17 May
Other references · 13
- 2021Learning Transferable Visual Models From Natural Language Supervisioncited by 33,456
- 2014Microsoft COCO: Common Objects in Contextcited by 17,498
- 2021LoRA: Low-Rank Adaptation of Large Language Modelscited by 14,084
- 2014Explaining and Harnessing Adversarial Examplescited by 7,287
- 2017Towards Deep Learning Models Resistant to Adversarial Attackscited by 6,326
- 2016Towards Evaluating the Robustness of Neural Networkscited by 2,976
- 2025InternVL3.5: Advancing Open-Source Multimodal Models in Versatility, Reasoning, and Efficiencycited by 1,419
- 2023Aligning Large Multimodal Models with Factually Augmented RLHFcited by 703
- 2018Object Hallucination in Image Captioningcited by 661
- 2021Recent Advances in Adversarial Training for Adversarial Robustnesscited by 276
- 2019Smooth Grad-CAM++: An Enhanced Inference Level Visualization Technique for Deep Convolutional Neural Network Modelscited by 118
- 2024From Redundancy to Relevance: Information Flow in LVLMs Across Reasoning Taskscited by 37
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- 2025Mitigating Behavioral Hallucination in Multimodal Large Language Models for Sequential Images
- 2026Decoding by Perturbation: Mitigating MLLM Hallucinations via Dynamic Textual Perturbation
- 2024Visual Hallucination: Definition, Quantification, and Prescriptive Remediations
- 2025Two Causes, Not One: Rethinking Omission and Fabrication Hallucinations in MLLMs
- 2026ReactBench: A Cause-Driven Benchmark for Multimodal Hallucination via Systematic Evaluation
- 2024Hallucination in Multimodal Foundation Models: A Survey on Causes, Corrections, and Evaluations