JetBrains Urging Customers to Patch Critical TeamCity Flaw that Enables OS Command Execution

JetBrains released emergency security updates addressing CVE-2026-63077, a critical unauthenticated remote code execution vulnerability in TeamCity On-Premises that allows attackers to bypass authentication via the agent polling protocol and execute arbitrary OS commands; fixed releases (2025.11.7 and 2026.1.3) and a security patch plugin are available, and JetBrains reported no known active exploitation at time of disclosure.