CVE-2026-100273 in YouTrack
Summary
by MITRE • 09/30/2026
In JetBrains YouTrack before 2026.2.19197 authorisation bypass in the scripts debugger allowed arbitrary code execution
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Analysis
by VulDB Data Team • 09/30/2026
The vulnerability identified in JetBrains YouTrack prior to version 2026.2.19197 represents a critical security failure within the platform's integrated scripting environment, specifically affecting the scripts debugger component. This flaw stems from an authorization bypass mechanism that allows unauthenticated or improperly authenticated users to interact with internal debugging interfaces intended for privileged administrators and developers. In enterprise environments where YouTrack is deployed as a central issue tracking and project management tool, such access controls are fundamental to maintaining data integrity and operational security. The absence of proper validation checks when handling requests directed at the debugger endpoint enables attackers to circumvent standard authentication protocols, effectively granting them elevated privileges without valid credentials or sufficient permission levels.
From a technical perspective, this authorization bypass exploits weaknesses in how the application processes session tokens and request metadata associated with the scripting engine. By manipulating these inputs, an attacker can invoke internal functions that are designed to execute arbitrary code within the context of the YouTrack server process. This capability transforms what might otherwise be a simple information disclosure or configuration error into a severe remote code execution vulnerability. The scripts debugger is typically used for troubleshooting complex automation workflows and custom integrations; however, when its access controls are compromised, it becomes an attack vector that allows malicious actors to inject and run arbitrary commands on the underlying operating system hosting the application server.
The operational impact of this vulnerability is profound, particularly in organizations relying on YouTrack for mission-critical project management and software development lifecycle tracking. Successful exploitation could lead to complete compromise of the affected server infrastructure. Attackers may exfiltrate sensitive data including customer information, proprietary code repositories linked via integrations, or internal communication logs stored within ticket descriptions and comments. Furthermore, because the execution occurs with the privileges of the application service account, lateral movement across the network becomes feasible if that account possesses broader system permissions. This could result in widespread disruption to business operations, loss of intellectual property, and potential regulatory non-compliance depending on the industry sector and data sensitivity involved.
This vulnerability aligns closely with Common Weakness Enumeration category CWE-287, which describes Improper Authentication, as well as CWE-94, Code Injection, due to the arbitrary code execution capability facilitated by the bypassed controls. In terms of tactical mapping under the MITRE ATT&CK framework, this scenario corresponds to techniques involving Initial Access through exploitation of application vulnerabilities and Execution via command or script invocation within a server environment. The ability to execute scripts remotely without proper authorization underscores the necessity for robust input validation and strict enforcement of role-based access control policies on all administrative interfaces.
To mitigate this risk, organizations must immediately upgrade their JetBrains YouTrack instances to version 2026.2.19197 or later, where these authorization checks have been hardened. Until patching is complete, it is advisable to restrict network access to the scripts debugger endpoints by configuring firewalls or reverse proxies to allow only trusted internal IP addresses and authenticated administrative users. Additionally, implementing strict monitoring for unusual activity patterns within the scripting engine logs can help detect attempted exploitation in real time. Regular security audits of custom integrations and third-party plugins are also recommended to ensure no additional attack surfaces exist that could be leveraged alongside this primary vulnerability.