Australian servers running JetBrains TeamCity On-Premises are under active attack, according to a warning issued by the Australian Cyber Security Centre on Aug 25 2026.

The critical authentication bypass flaw, tracked as CVE-2026-63077 and rated 9.8 out of 10 in severity, allows unauthenticated attackers with network access to run arbitrary operating system commands, the Australian Signals Directorate's ACSC said, iTnews reports.