Notification spam is the repeated delivery of unwanted alerts, often through browsers, apps, or push services, until users stop paying attention. It is not always a classic intrusion; it is a form of abuse that targets the user interface and the trust users place in it. When alerts arrive too often, legitimate warnings can blend into the noise.
In cyber security, notification spam matters because it can hide phishing prompts, social-engineering lures, or malicious permission requests inside a flood of harmless-looking messages. Attackers may use it to exhaust attention, trigger accidental clicks, or make users dismiss real security warnings. Defenders respond with rate limits, abuse detection, permission controls, reputation systems, and filtering that suppresses repeated or suspicious alerts before they reach the user. The goal is to preserve the signal value of notifications so important messages still stand out.