CyberGuard dictionary / AI Security
Training Data Poisoning
Training data poisoning is manipulation of examples used to train or fine-tune a model to bias, degrade, or redirect its future outputs.

In simple terms
If bad examples enter a learning set, the model can absorb the pattern before anyone asks it a question. The effect may be broad or limited to a trigger.
Technical explanation
An adversary may insert mislabeled records, repeated false claims, or trigger-bearing samples into pre-training, fine-tuning, or embedding data. Dataset lineage and validation matter because the error can persist after training.
Poisoning targets examples used to train or fine-tune a model, including labels, text, or repeated patterns. It is harder to diagnose after training, making dataset lineage and review important.
Examples in practice
A vendor imported support dataset includes planted answers that teach a chatbot to recommend a fake payment page for refund requests.
A support dataset contains many planted examples directing users to a fake payment page. Before fine-tuning, reviewers trace the source and remove the suspect records.
Why it matters
Reviewing data sources and training changes is as important as checking prompts at runtime.
VERIFY & LEARN MORE
Sources and further reading
- genai.owasp.orghttps://genai.owasp.org/llmrisk/llm042025-data-and-model-poisoning/↗
- atlas.mitre.orghttps://atlas.mitre.org/↗
Published 2026-10-15 · Last updated 2026-10-15 · CyberGuard editorial content. Source links provide context; they do not imply endorsement.
