CVE-2026-28193: JetBrains YouTrack Auth Bypass Vulnerability

CVE-2026-28193 Overview

A Missing Authorization vulnerability (CWE-862) has been identified in JetBrains YouTrack, a project management and issue tracking software. In versions prior to 2025.3.121962, applications were able to send requests to the app permissions endpoint without proper authorization checks. This flaw allows unauthorized access to modify application permissions, potentially compromising the integrity of the YouTrack instance.

Critical Impact

Unauthorized applications can send requests to the app permissions endpoint, potentially allowing attackers to manipulate app permissions without proper authorization.

Affected Products

• JetBrains YouTrack versions before 2025.3.121962

Discovery Timeline

• 2026-02-25 - CVE CVE-2026-28193 published to NVD
• 2026-02-26 - Last updated in NVD database

Technical Details for CVE-2026-28193

Vulnerability Analysis

This vulnerability stems from a Missing Authorization flaw (CWE-862) in JetBrains YouTrack's application permissions management functionality. The affected endpoint responsible for handling app permissions lacks proper authorization validation, allowing any application to send requests and potentially modify permission configurations without authentication or proper access control checks.

The network-based attack vector requires no user interaction and no privileges, making it accessible to remote attackers. While the vulnerability does not impact confidentiality or availability, it poses a risk to system integrity by allowing unauthorized modification of application permissions.

Root Cause

The root cause is a missing authorization check on the app permissions endpoint in JetBrains YouTrack. The application fails to properly validate whether incoming requests to modify or query application permissions originate from authorized sources. This allows any application—including potentially malicious ones—to interact with the permissions endpoint without proper access control enforcement.

Attack Vector

The vulnerability is exploitable over the network without requiring authentication or user interaction. An attacker could craft requests targeting the app permissions endpoint to:

1. Enumerate existing application permissions configurations
2. Modify permissions for installed applications
3. Potentially escalate privileges for malicious apps within the YouTrack environment

The attack does not require any special conditions to exploit, as the authorization check is entirely absent from the vulnerable endpoint.

The vulnerability occurs in the app permissions handling mechanism where authorization validation should be enforced but is missing. When requests are received at the permissions endpoint, the application processes them without verifying the caller's authorization status. For detailed technical information, refer to the JetBrains Security Advisory.

Detection Methods for CVE-2026-28193

Indicators of Compromise

• Unexpected changes to application permissions within YouTrack
• Unusual API requests targeting the app permissions endpoint from unknown sources
• Anomalous application behavior or new apps with elevated permissions that were not explicitly granted

Detection Strategies

• Monitor YouTrack access logs for requests to the app permissions endpoint from unauthorized or unexpected sources
• Implement network monitoring to detect unusual traffic patterns targeting YouTrack API endpoints
• Audit application permission configurations regularly to identify unauthorized modifications

Monitoring Recommendations

• Enable verbose logging for YouTrack API endpoints, particularly those related to application management
• Set up alerting for permission changes that occur outside of normal administrative workflows
• Review installed applications and their permission levels periodically for anomalies

How to Mitigate CVE-2026-28193

Immediate Actions Required

• Upgrade JetBrains YouTrack to version 2025.3.121962 or later immediately
• Review existing application permissions for any unauthorized modifications
• Audit access logs for any suspicious activity targeting the permissions endpoint prior to patching

Patch Information

JetBrains has released a security patch addressing this vulnerability in YouTrack version 2025.3.121962. Organizations should update to this version or later to remediate the issue. For complete details on security fixes, refer to the JetBrains Security Issues Fixed page.

Workarounds

• Restrict network access to the YouTrack instance using firewall rules to limit exposure
• Implement web application firewall (WAF) rules to block unauthorized requests to the permissions endpoint
• Consider placing YouTrack behind a reverse proxy with additional authentication requirements until the patch can be applied

# Example: Restrict access to YouTrack using iptables
# Only allow access from trusted network ranges
iptables -A INPUT -p tcp --dport 8080 -s 10.0.0.0/8 -j ACCEPT
iptables -A INPUT -p tcp --dport 8080 -j DROP