A targeted data poisoning attack is a machine learning security exploit in which an adversary injects maliciously crafted or modified samples into a training dataset to alter a model predictions on specific target inputs. Unlike untargeted poisoning attacks that degrade overall system accuracy or cause widespread classification failures, targeted attacks aim to force a precise incorrect outcome for a chosen input while leaving the model performance on other data intact. This selective interference makes the compromise stealthy and difficult to detect during standard evaluation, as the poisoned model maintains normal functionality on typical benchmark tests while failing specifically when encountering the designated target at inference time.