2025 was a big year for cybersecurity, with major cyberattacks, data breaches, threat groups reaching new notoriety levels, and, of course, zero-day vulnerabilities exploited in incidents.

Some stories, though, were more impactful or popular with our readers than others.

Below are fifteen of what BleepingComputer believes are the most impactful cybersecurity topics of 2025, with a summary of each. These stories are in no particular order.