CVE-2026-63077: Critical unauthenticated remote code execution in JetBrains TeamCity
Brief
Overview
On July 27, 2026, JetBrains published a security advisory for CVE-2026-63077 , a critical unauthenticated vulnerability affecting all versions of TeamCity On-Premises. The issue is classified as deserialization of untrusted data and has a CVSS score of 9. 8 .
An unauthenticated remote attacker with HTTP(S) access to a TeamCity server can exploit the agent polling protocol to bypass authentication checks and execute arbitrary operating system commands with the privileges of the TeamCity server process.
In the blog post that JetBrains shared in tandem with CVE publication, they stated that attackers who exploit the vulnerability can read stored credentials and compromise CI/CD pipeline integrity. The impact of successful exploitation depends on the operating system privileges granted to the TeamCity server process.