CVE-2026-100279 in YouTrack
Summary
by MITRE • 09/30/2026
In JetBrains YouTrack before 2026.2.19197 changing an integration URL exposed its stored credentials
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 09/30/2026
The vulnerability identified in JetBrains YouTrack prior to version 2026.2.19197 represents a critical information disclosure flaw within the application's integration management subsystem. This security defect arises from improper handling of sensitive configuration data when administrators modify existing webhook or third-party service integrations. Specifically, the system fails to mask or sanitize stored credentials during the update process, resulting in their exposure through standard API responses and user interface elements that are intended for routine administrative tasks rather than secret management.
From a technical perspective, this flaw is classified under CWE-200 as an Information Exposure vulnerability, specifically falling into the category of exposed sensitive information within error messages or debug data, although here it manifests in normal operational output. When an administrator navigates to the integration settings page and modifies any parameter such as the target URL, the backend service processes the request by retrieving the existing configuration object from the database. Instead of stripping out protected fields like API keys, tokens, or passwords before serializing the response for the frontend client, the application includes these plaintext values in the JSON payload returned to the browser. This behavior persists even if the administrator does not explicitly change the credentials themselves, indicating a systemic failure in data sanitization logic during partial updates of configuration objects.
The operational impact of this vulnerability is severe due to the high privilege level required for exploitation and the sensitivity of the exposed data. An authenticated user with administrative privileges or access to integration management features can trivially extract these secrets by inspecting network traffic via browser developer tools or intercepting API calls using a proxy like Burp Suite. The exposure allows attackers who have gained initial foothold as an admin-level user, or those exploiting other vulnerabilities such as Cross-Site Scripting (XSS) that grants access to the integration settings page, to harvest credentials for external services connected to YouTrack. These may include GitHub tokens, Slack webhooks, Jira API keys, or custom webhook secrets used for CI/CD pipelines and monitoring systems.
This vulnerability aligns with MITRE ATT&CK technique T1530, Data from Local System, as it involves the collection of data stored locally on the system that is not actively being transmitted over a network but is accessible through local application interactions. Furthermore, it relates to T1078, Valid Accounts, because exploitation typically requires valid administrative credentials first. The ability to exfiltrate these secrets enables lateral movement and privilege escalation across integrated ecosystems. For instance, an attacker could use exposed GitHub tokens to access private repositories or deploy malicious code via CI/CD pipelines linked through the compromised YouTrack instance.
Mitigation strategies must focus on immediate patching and defensive configuration changes. Organizations running affected versions of JetBrains YouTrack should upgrade immediately to version 2026.2.19197 or later, where this sanitization logic has been corrected to ensure credentials are never returned in API responses unless explicitly requested through a dedicated secret management interface with additional authentication checks. In the interim, administrators should rotate all exposed credentials for integrations that were modified during the vulnerable period. It is also recommended to implement strict access controls on integration settings pages and monitor audit logs for unusual patterns of configuration changes or data retrieval operations associated with these endpoints.