Critical TeamCity Flaw Lets Unauthenticated Attackers Execute Commands Remotely

A critical remote code execution vulnerability in JetBrains TeamCity On-Premises is exposing servers to unauthenticated compromise, allowing attackers to execute arbitrary commands without valid credentials. The flaw, tracked as CVE-2026-63077 , affects all on-premises versions of TeamCity and has been assigned a critical severity due to its potential to fully compromise CI/CD environments. The vulnerability allows an attacker with HTTP or HTTPS access to a TeamCity server to…