CVE-2026-100274 in YouTrack
Summary
by MITRE • 09/30/2026
In JetBrains YouTrack before 2026.2.19197 project Admin could trigger DoS via a notification template
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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 significant availability risk within the application's administrative functionality, specifically targeting users with Project Administrator privileges. This flaw allows an authenticated attacker who holds this elevated role to execute a Denial of Service attack against the target instance by manipulating notification templates. The core technical issue stems from insufficient validation or resource management when processing complex or malformed data structures embedded within these template configurations. When such a maliciously crafted template is triggered, it causes the server-side rendering engine to enter an infinite loop, consume excessive memory resources, or exhaust available system handles, thereby preventing legitimate users from accessing the application and disrupting ongoing workflows.
From a technical perspective, this vulnerability aligns with CWE-400, which describes Uncontrolled Resource Consumption, as well as CWE-787, Out-of-bounds Write if the issue involves buffer overflows during template parsing, though resource exhaustion is the primary observed behavior in typical notification engine exploits. The attack vector leverages the legitimate administrative interface, meaning that an attacker does not need to bypass authentication or exploit a separate entry point but rather abuses their existing permissions within a specific project context. This highlights a critical design flaw where high-privilege actions are not sufficiently sandboxed from causing systemic instability. In many enterprise environments, this could be particularly damaging if the Project Admin role is granted broadly or if there is insufficient monitoring of administrative activities that impact server performance metrics significantly.
The operational impact of this vulnerability extends beyond simple service interruption. A successful exploitation can lead to prolonged downtime for critical project management operations, potentially affecting team collaboration, issue tracking, and release planning processes dependent on YouTrack. Since the attack requires Project Admin access, it poses a threat primarily in environments where privilege escalation has already occurred or where administrative rights are overly permissive. The resulting service unavailability forces administrators to perform manual interventions such as restarting services or rolling back configuration changes, which introduces operational overhead and potential data inconsistency risks if not handled carefully during recovery procedures.
To mitigate this risk, organizations must immediately upgrade their JetBrains YouTrack instances to version 2026.2.19197 or later, where the underlying template processing logic has been hardened against such resource exhaustion attacks. In addition to patching, it is advisable to implement strict access controls for Project Admin roles, ensuring that only trusted individuals can modify notification templates. Monitoring solutions should be configured to detect abnormal spikes in CPU usage or memory consumption associated with notification service threads, which may indicate an ongoing exploitation attempt. Furthermore, adopting the principle of least privilege and regularly auditing administrative permissions can reduce the attack surface available to potential insiders or compromised accounts seeking to disrupt system availability through this specific vector.