JetBrains fixes critical unauthenticated RCE vulnerability (CVE-2026-63077) in TeamCity On-Premises

JetBrains has released a fix for a critical unauthenticated remote code execution (RCE) vulnerability, tracked as CVE-2026-63077, affecting TeamCity On-Premises. The flaw, exploitable via the TeamCity agent polling protocol, could allow attackers to bypass authentication and execute OS commands with server privileges. Administrators are urged to upgrade self-hosted servers immediately or apply a security patch plugin.