CISA Warns of Active Exploitation of Critical JetBrains TeamCity RCE Flaw (CVE-2026-63077)

The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has flagged a newly patched critical security flaw, CVE-2026-63077, in on-premise versions of JetBrains TeamCity as being under active exploitation. This deserialization of untrusted data vulnerability could allow an unauthenticated attacker to bypass authentication checks and execute arbitrary operating system commands with the privileges of the TeamCity server process. Users are urged to apply updates immediately.