Executive brief
JetBrains TeamCity, a platform used by software teams to automate building and testing code, is vulnerable to a security flaw in its build agent registration process. An unauthenticated attacker can inject malicious scripts into the system, which could allow them to hijack administrator sessions or steal sensitive data when a legitimate user views the affected management pages. This could lead to unauthorized access to the software development pipeline and corporate intellectual property.
Technical details
A stored cross-site scripting (XSS) vulnerability exists in JetBrains TeamCity before version 2026.1.2. The flaw is located in the agent registration component, which fails to properly neutralize user-supplied input (CWE-79). An unauthenticated remote attacker can exploit this by registering a malicious build agent with a crafted payload. When a TeamCity administrator or authorized user interacts with the agent management interface, the malicious script executes in their browser context. This can lead to session hijacking, unauthorized configuration changes, or data exfiltration. The issue is resolved in TeamCity version 2026.1.2.
Affected products
- JetBrains TeamCity before 2026.1.2
Timeline
- 2026-07-10: disclosed
- 2026-07-10: advisory