when AI (like, all of them) makes stuff up but says it with full confidence and a bibliography.
Model output that is fluent and plausible but factually incorrect, unsupported by training data, or entirely fabricated. Hallucination is not a bug — it is an inherent property of how generative models produce text. The model does not “know” things; it predicts the next statistically likely token. When prediction diverges from fact, the output reads like confident expertise. It is neither. OWASP classifies this under LLM09 Misinformation.
Why It Matters
Hallucination is one of the few AI risks that gets more dangerous as the model gets better. A mediocre model produces visibly clumsy output. A frontier model produces hallucinations that are linguistically indistinguishable from fact. The better your AI writes, the harder its fabrications are to catch.
This is a board-level problem, not a prompt-engineering problem. When AI-generated content enters legal filings, regulatory submissions, board papers, customer communications, or medical records, a hallucination is no longer an amusing chatbot glitch. It is a governance failure with documented consequences: sanctions, liability, reputational destruction, and regulatory intervention.
The structural challenge is that hallucination cannot be eliminated. It can be reduced through retrieval-augmented generation, fine-tuning, evaluation pipelines, and output grounding. But the residual rate is never zero. Governance, therefore, must assume hallucinations will reach production and design the detection, escalation, and correction mechanisms accordingly.
The Stress Test
A regulator asks your organisation to demonstrate that outputs from your customer-facing AI are factually accurate. You point to your RAG pipeline. The regulator asks for the evaluation results. You have none — because the pipeline was never tested against ground truth after deployment. Your monitoring tracks latency, throughput, and error rates. It does not track whether the answers are true.
The system has been live for nine months. You cannot say how many hallucinated responses reached customers. You cannot say because you have no mechanism to count them. That absence is the finding.
In the Wild
Attorney Steven Schwartz used ChatGPT to research case law for a personal injury lawsuit against Avianca Airlines. The tool produced six case citations, complete with judge names, docket numbers, internal cross-references, and lengthy quotations from “opinions.” All six cases were entirely fabricated. The hallucinated cases even cited other hallucinated cases, creating a fictional web of legal precedent.
Judge P. Kevin Castel sanctioned the attorneys $5,000 for violating Rule 11 of the Federal Rules of Civil Procedure. The case became the global reference point for AI hallucination risk overnight.
The model was not confused. It was doing exactly what it was designed to do: predict the next plausible token. Plausible and true are different properties.
An analysis of peer review submissions to NeurIPS 2025 — one of the world’s top machine learning conferences — identified 100 fabricated citations across submitted papers. The taxonomy: 66% total fabrication, 27% partial attribute corruption (real author, fake paper), 4% identifier hijacking, 2% placeholder hallucination, 1% semantic hallucination.
The AI researchers studying hallucination were submitting hallucinated references to the conference studying AI. That sentence is not a joke. It is the citation: arXiv:2602.05930.
Air Canada’s customer service chatbot told a bereaved passenger he could buy a full-price ticket and apply for a bereavement discount within 90 days. This policy did not exist. The airline’s actual policy required bereavement fares to be requested before travel. When the passenger was denied the refund, he took Air Canada to the Civil Resolution Tribunal.
Air Canada argued the chatbot was “a separate legal entity.” The tribunal disagreed. Ruling: “It should be obvious to Air Canada that it is responsible for all the information on its website. It makes no difference whether the information comes from a static page or a chatbot.” Air Canada paid $812 in damages.
The chatbot hallucinated a policy. The court made it real. That is the governance gap in one sentence.
How to Govern It
You cannot eliminate hallucination. You can govern the blast radius.
Within the AI Enterprise Control Index, hallucination governance spans multiple layers and shields:
- Observability (S4) — Runtime detection of output quality degradation, confidence monitoring, and factual grounding checks. If you are not measuring whether outputs are true, you are not monitoring. You are logging.
- AI Engineering (L5) — Retrieval-augmented generation pipelines with citation verification, evaluation plans with ground-truth benchmarks, and model evaluation gates that test for factual accuracy before deployment.
- Ethics & Fairness (L2) — Explainability standards requiring that AI outputs include provenance indicators. A user should know whether a response is grounded in retrieved evidence or generated from the model’s parametric memory.
- GRC (S1) — Evidence Factory captures hallucination detection test results, evaluation benchmarks, and incident records as governance artifacts.
- Applications & Agents (L4) — System-level controls: output disclaimers, confidence thresholds below which responses are withheld or escalated, and circuit breakers for automated workflows.
When It's Relevant
Every deployment of a generative AI system. Without exception. Hallucination is not a risk that applies only to high-risk systems. A customer-facing chatbot that fabricates a return policy (Air Canada), a legal research tool that invents case law (Mata v. Avianca), and an internal assistant that hallucinates compliance status are all hallucination incidents — each with different blast radii, all requiring detection.
Hallucination risk is highest when:
- The query falls outside the model’s training distribution
- The system has no retrieval layer to ground responses in verified documents
- The output is consumed by humans who lack the domain expertise to detect fabrication
- The output enters an automated workflow with no human review checkpoint
- The organisation has no post-deployment evaluation measuring factual accuracy
Related Terms
References
- [1] Huang, L., Yu, W., Ma, W., Zhong, W., Feng, Z., Wang, H., Chen, Q., Peng, W., Feng, X., Qin, B. and Liu, T. (2024) ‘A Survey on Hallucination in Large Language Models: Principles, Taxonomy, Challenges, and Open Questions’, arXiv preprint, arXiv:2311.05232v2. Available at: arxiv.org/abs/2311.05232.
- [2] Ji, Z., Lee, N., Frieske, R., Yu, T., Su, D., Xu, Y., Ishii, E., Bang, Y., Madotto, A. and Fung, P. (2023) ‘Survey of Hallucination in Natural Language Generation’, ACM Computing Surveys, 55(12), pp. 1–38. doi: 10.1145/3571730.
- [3] OWASP Foundation (2025) OWASP Top 10 for Large Language Model Applications v2025.1. LLM09: Misinformation. Available at: owasp.org/www-project-top-10-for-large-language-model-applications.
- [4] NIST (2024) Artificial Intelligence Risk Management Framework: Generative AI Profile (AI 600-1). National Institute of Standards and Technology, U.S. Department of Commerce.
- [5] Mata v. Avianca, Inc. (2023) No. 22-cv-01461 (PKC), United States District Court, Southern District of New York. Sanctions order, 22 June 2023.
- [6] Moffatt v. Air Canada (2024) Civil Resolution Tribunal, British Columbia, Canada. Decision No. CRT-2024-00234.
- [7] Raji, I.D., Smart, A., White, R.N., Mitchell, M., Gebru, T., Hutchinson, B., Smith-Loud, J., Theron, D. and Barnes, P. (2020) ‘Closing the AI Accountability Gap: Defining an End-to-End Framework for Internal Algorithmic Auditing’, Proceedings of the 2020 Conference on Fairness, Accountability, and Transparency (FAT*), pp. 33–44.
AI Enterprise Control Index v6.0 · Glossary · June 2026 · i-DEPOT 158508 (BOIP) · CC BY-NC-ND 4.0
By Jeroen Janssen, Apparens