CISA Flags TeamCity CVE-2026-63077 RCE Flaw Under Active Exploitation in the Wild

The US Cybersecurity and Infrastructure Security Agency has reported that a security flaw in on-premise versions of JetBrains TeamCity is being actively exploited. The vulnerability, identified as CVE-2026-63077, has a high CVSS score of 9.8 and involves the deserialization of untrusted data. This could enable an unauthenticated attacker with access to a TeamCity server to carry out remote code execution. The issue has been patched, but its active exploitation in the wild has been confirmed by CISA. The vulnerability affects on-premise TeamCity installations, making them a potential target for attackers.