The Korea Atomic Energy Research Institute confirmed that an unidentified external actor accessed some systems through a VPN vulnerability after a media report alleged a breach and possible North Korean hacking. KAERI said it blocked the attacker IP address, applied VPN security updates, and was investigating the intrusion actor and damage scope with relevant authorities. The source notes that claims of a North Korea-linked hacking group were still under analysis and that no confirmed damage had been established at the time, so attribution remains unresolved. KAERI attributed an earlier “no hacking incident” response to a staff mistake while the suspected intrusion was still being investigated.