CVE-2026-103490 in YouTrack
Summary
by MITRE • 10/01/2026
In JetBrains YouTrack before 2026.2.19422 privilege escalation was possible via user group links
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 10/01/2026
The vulnerability identified in versions of JetBrains YouTrack prior to build 2026.2.19422 represents a critical security flaw centered on improper access control mechanisms within the application's user management subsystem. Specifically, this issue manifests as a privilege escalation vector that allows an authenticated attacker with lower-level permissions to manipulate or exploit links associated with user groups. In web-based enterprise applications like YouTrack, which serves as an issue tracking and project management platform, the integrity of group memberships is paramount for maintaining proper segregation of duties and enforcing role-based access control policies. The flaw arises from insufficient validation when processing requests related to these group associations, allowing malicious actors to bypass intended restrictions on administrative or elevated privileges.
From a technical perspective, this vulnerability aligns with CWE-269, which classifies Improper Privilege Control. It also maps closely to the MITRE ATT&CK technique T1078, Valid Accounts, specifically within the context of lateral movement and privilege escalation where an attacker leverages valid credentials but exploits misconfigurations or logic flaws to gain higher-level access. The core issue lies in how the backend handles HTTP requests that modify group memberships. If the application fails to verify whether the authenticated user has sufficient authority to perform actions on specific groups, particularly those containing administrators or users with elevated rights, it creates a pathway for unauthorized privilege acquisition. This could involve adding oneself to an administrative group, modifying existing members of such groups, or exploiting API endpoints that do not strictly enforce ownership and permission checks during link resolution operations.
The operational impact of this vulnerability is severe, as successful exploitation can lead to complete compromise of the YouTrack instance's security posture. An attacker who achieves privilege escalation through these user group links could gain administrative access, enabling them to view sensitive project data, modify issue tracking workflows, delete critical records, or install malicious plugins that persist across sessions. This undermines the confidentiality, integrity, and availability of the organization’s development processes and intellectual property stored within the system. Furthermore, because YouTrack is often integrated with other CI/CD pipelines and source code repositories via webhooks and API integrations, compromising an administrator account could serve as a foothold for broader network intrusion, potentially leading to supply chain attacks or data exfiltration on a larger scale.
Mitigation strategies must prioritize immediate patching of the affected software version. Organizations running versions earlier than 2026.2.19422 should upgrade to this patched release or any subsequent version where JetBrains has addressed the access control logic flaws. In environments where upgrading is not immediately feasible, temporary mitigations include restricting network access to the YouTrack instance to trusted IP ranges only and ensuring that administrative accounts are protected by multi-factor authentication to reduce the risk of credential theft preceding exploitation. Additionally, security teams should audit user group configurations regularly to ensure no unauthorized users hold elevated privileges and monitor system logs for anomalous activities related to group membership changes or unusual API calls targeting user management endpoints. Continuous monitoring using intrusion detection systems configured to flag privilege escalation attempts can provide early warning indicators if the vulnerability is exploited in the wild before patches are applied.