TeamCity CVSS 9.8 RCE demands immediate patching — here's what you need to do

JetBrains disclosed CVE-2026-63077 on July 27, 2026 — a CVSS 9.8 unauthenticated remote code execution flaw affecting every on-premises TeamCity instance. No active exploitation has been detected yet, but the clock is ticking: TeamCity's history with state-sponsored attackers makes this a drop-everything patch scenario.