CVE-2026-103495 Overview
CVE-2026-103495 is a missing authorization vulnerability in JetBrains YouTrack versions prior to 2026.2.19422. The flaw allows an authenticated user with low privileges to trigger a reload of translation catalogs over the network. The weakness maps to [CWE-862] Missing Authorization, where an application fails to perform an access control check before executing a sensitive operation. Successful exploitation does not expose data or alter integrity, but can affect availability of the YouTrack instance by forcing unnecessary catalog reload operations.
Critical Impact
Authenticated attackers can reload translation catalogs without proper authorization, impacting availability of the JetBrains YouTrack service.
Affected Products
- JetBrains YouTrack versions before 2026.2.19422
Discovery Timeline
- 2026-10-01 - CVE CVE-2026-103495 published to NVD
- 2026-10-01 - Last updated in NVD database
Technical Details for CVE-2026-103495
Vulnerability Analysis
The vulnerability resides in a YouTrack endpoint that triggers reloading of translation catalogs. The endpoint does not verify whether the calling user holds the required administrative privilege. Any authenticated low-privilege user can therefore invoke the operation and force the server to reinitialize localization resources.
Translation catalog reloads consume server resources. Repeated invocation can degrade performance, delay request handling, and reduce availability for legitimate users. The vulnerability does not compromise confidentiality or integrity of project data, issues, or user records.
Root Cause
The root cause is a missing authorization check [CWE-862] on the handler that services translation catalog reload requests. The code path validates authentication but does not enforce role-based access control before executing the privileged action. This pattern allows horizontal exposure of administrative functionality to any logged-in user.
Attack Vector
Exploitation requires network access to the YouTrack instance and valid low-privilege credentials. No user interaction is needed. An attacker authenticates to YouTrack, then issues the request that triggers the translation catalog reload. Repeated requests amplify the availability impact. See the JetBrains Security Issues Fixed advisory for vendor details.
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Stop Identity AttacksDetection Methods for CVE-2026-103495
Indicators of Compromise
- Repeated HTTP requests from a single authenticated session targeting translation or localization reload endpoints.
- Unexpected spikes in YouTrack CPU and memory usage correlated with low-privilege user sessions.
- Application logs showing translation catalog reload events outside of administrative maintenance windows.
Detection Strategies
- Review YouTrack audit logs for translation catalog reload operations performed by non-administrative accounts.
- Correlate authentication logs with endpoint access patterns to identify low-privilege users calling administrative endpoints.
- Baseline normal catalog reload frequency and alert on deviations.
Monitoring Recommendations
- Forward YouTrack application and access logs to a centralized SIEM for query and retention.
- Monitor service availability metrics such as request latency and error rates on the YouTrack host.
- Enable alerting on repeated requests to localization or administrative endpoints from the same session.
How to Mitigate CVE-2026-103495
Immediate Actions Required
- Upgrade JetBrains YouTrack to version 2026.2.19422 or later.
- Audit active user accounts and revoke credentials that are no longer required.
- Review recent access logs for anomalous requests to translation or administrative endpoints.
Patch Information
JetBrains fixed the issue in YouTrack 2026.2.19422. The patched build enforces the required authorization check on the translation catalog reload endpoint. Refer to the JetBrains Security Issues Fixed page for the official advisory and release notes.
Workarounds
- Restrict network access to the YouTrack instance to trusted networks and VPN users where feasible.
- Enforce strong authentication and limit account provisioning to reduce the pool of users able to reach the endpoint.
- Place a reverse proxy or web application firewall in front of YouTrack to rate-limit requests to administrative endpoints.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
