CVE-2026-59793 in TeamCity
Summary
by MITRE • 07/10/2026
In JetBrains TeamCity before 2026.1.2 arbitrary file access was possible via the Perforce VCS integration
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Analysis
by VulDB Data Team • 07/10/2026
JetBrains TeamCity versions prior to 2026.1.2 contained a critical security vulnerability in the Perforce Version Control System integration that allowed attackers to perform arbitrary file access operations. This vulnerability emerged from insufficient input validation and path traversal mechanisms within the VCS integration module, specifically affecting how TeamCity handled file paths during Perforce repository operations. The flaw enabled malicious actors to manipulate file access requests through specially crafted parameters that bypassed normal security boundaries.
The technical implementation of this vulnerability stemmed from improper sanitization of user-supplied data in the Perforce integration component. When TeamCity processed VCS operations involving Perforce repositories, it failed to adequately validate or escape file path references, creating opportunities for path traversal attacks. Attackers could exploit this weakness by constructing malicious file access requests that would be interpreted by the underlying Perforce client as legitimate operations, thereby gaining unauthorized access to files outside of the intended repository scope.
The operational impact of this vulnerability was severe and multifaceted across enterprise environments utilizing TeamCity with Perforce integration. Organizations faced potential exposure of sensitive source code, configuration files, build artifacts, and other proprietary data that might reside on the same system as the TeamCity server. The vulnerability could be exploited remotely without authentication in certain configurations, making it particularly dangerous for organizations with exposed TeamCity instances. Additionally, attackers could potentially access system files or perform destructive operations if proper file permissions were not enforced.
This vulnerability aligns with CWE-22 Path Traversal and CWE-73 Improper Neutralization of Special Elements in Output Used by a Downstream Component, both of which are commonly exploited in VCS integration attacks. From an ATT&CK perspective, this issue maps to T1059 Command and Scripting Interpreter and T1566 Phishing, as attackers could leverage the access to extract sensitive information or establish persistence through compromised build systems. Organizations should implement immediate mitigations including upgrading to TeamCity 2026.1.2 or later versions, enforcing strict network segmentation, implementing proper access controls for VCS integrations, and conducting thorough security reviews of all integration components. Regular monitoring of file access patterns and implementing automated vulnerability scanning tools specifically targeting build server configurations would further enhance protection against similar threats.