Risk · R-086 · Model Performance & Reliability
Stale model knowledge
A model answers from knowledge that ended at its training cut-off, on matters such as rates, rules or products that have since changed.
- Severity
- Medium
- Audience
- Practitioner
- Frameworks
- Article 13 · Confabulation
- Responsible AI domain
- Lifecycle stage
- Reviewed
- 2026-11-10
What it is
A language model knows the world as it was when its training data was collected. It does not know what has changed since and, unless told, does not flag that its answer may be out of date. For stable subjects this is immaterial. For regulation, prices, product terms and current events, the model's knowledge may be confidently wrong.
How it happens
- A question depends on a rule or rate that changed after the cut-off.
- The system relies on the model's memory instead of supplying current documents.
- A retrieval source is itself out of date.
- Users are not told the date of the model's knowledge.
Why it matters
Out-of-date information is presented as current. In regulated communications that can mean quoting a superseded rule, a withdrawn product or an old limit, with the consequences of any other inaccurate statement.
Warning signs
- Answers cite figures or rules that have been replaced.
- The system has no source of current information for time-sensitive topics.
- Nobody knows the model's training cut-off.
- Test questions do not include recent changes.
Mitigating controls
Primary controls
- Retrieval grounding and citation Preventive
- Supplies current information at answer time. The system answers only from retrieved, approved sources, cites the source for each statement, and declines where the sources do not support an answer.
Supporting controls
- Evaluation suite and regression testing Detective
- Includes time-sensitive questions in the test set. A maintained set of test cases with expected results is run on every change to model, prompt, data or tools, and the results are compared with the approved baseline.
- Information for deployers and users Directive
- Tells users the model's knowledge date. Those who operate and use an AI system receive current, usable instructions covering its purpose, performance, limitations, the meaning of its outputs and the oversight it needs.
Framework and clause references
| Framework | Clause | Title |
|---|---|---|
| EU AI Act | Article 13 | Transparency and provision of information to deployers Limitations must be stated. |
| NIST Generative AI Profile (NIST AI 600-1) | Confabulation | Confabulation Out-of-date answers present as confabulation. |
Sources
- EU AI Act: Regulation (EU) 2024/1689 European Union (EUR-Lex) · official text
- NIST Generative AI Profile NIST · framework
Related terms
How to cite
Axiom Verity (2026). Stale model knowledge. Reference Library, R-086. https://axiom-verity.com/risks/stale-model-knowledge. Reviewed 2026-11-10.
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