False warnings of nuclear radiation, chemical attack and incoming missiles briefly turned a tool meant to protect civilians into a source of alarm in wartime Ukraine. Hours later, Russia reported a similar breach of its own emergency-warning application, leaving both countries to confront the vulnerability of systems relied on during air raids.

In Ukraine, users of the nationwide alert app received messages late on Sunday warning of a possible radiation threat in Kyiv, street fighting and an Oreshnik missile strike. The alerts, some of which contained spelling mistakes and appeared in English as well as Ukrainian, prompted fear among some residents while others quickly suspected the service had been compromised. “I was briefly terrified,” a Kyiv resident identified as Nina said. “I lay on my bed and wondered what was coming.”¹

Ukraine’s air force said the application appeared to have been subjected to “enemy influence” and stressed that there was no radiation threat.² Ukrainian authorities temporarily suspended the channel and urged users not to open links in suspicious notifications. Reporting described the breach as an unusually serious disruption because the app is a central route through which officials warn civilians to seek shelter from drones and missiles.³

Russian officials gave a broadly similar account of their own incident, saying a “massive cyber-attack” on the emergencies ministry’s mobile application had enabled attackers to send false information to the public.² But attribution remains unresolved. A Russian Telegram channel reportedly linked the incident to the group Hitcore, while a Ukrainian hacker group separately claimed it had sent false nuclear-warhead alerts inside Russia; neither assertion was independently verified.¹³

The parallel disruptions came as military strikes continued and a local ceasefire around Oleshky in the Kherson region expired. The episode underscored a shared risk for civilians on both sides: in an information war, false alarms can erode confidence precisely when genuine warnings may be most urgent.