CVE-2026-100263
MediumCVSS 4.7Exploitation Probability (EPSS)
Low risk8th percentile - higher than 8% of all known CVEs
Summary
In JetBrains YouTrack before 2026.2.18991 stored HTML injection via the User-Agent header was possible. Malicious content could be stored and displayed to other users.
Risk Assessment
Stored HTML injection can lead to phishing, session theft, or other browser-based attacks on the victim. The risk affects all users viewing infected pages.
Recommendation
Update JetBrains YouTrack to version 2026.2.18991 or later. Consider implementing security headers and input sanitization.
Other vulnerabilities in JetBrains YouTrack
See all- CVE-2026-103497Medium
In JetBrains YouTrack before 2026.2.19422, SSRF was possible via the GitHub VCS integration.
- CVE-2026-103496Medium
In JetBrains YouTrack before 2026.2.19422, iDOR in inbox threads allowed reading other users' notifications.
- CVE-2026-103495Medium
In JetBrains YouTrack before 2026.2.19422, missing authorisation allowed reloading of translation catalogs.
- CVE-2026-103493High
In JetBrains YouTrack before 2026.2.19422, stored XSS via Mermaid and LaTeX content was possible. The vulnerability allows execution of arbitrary script in the user's browser.
- CVE-2026-103492Medium
In JetBrains YouTrack before 2026.2.19422, DoS attack was possible via crafted PSD attachments.
- CVE-2026-103491Medium
In JetBrains YouTrack before 2026.2.19422, iDOR in the issue activities API allowed reading restricted issues.
- CVE-2026-86478Critical
In JetBrains YouTrack before 2025.3.161254 and 2026.1.14042, improper authentication in YouTrack Helpdesk allowed unauthenticated account takeover via a self-asserted email address.
- CVE-2026-62422Critical
In JetBrains YouTrack before versions 2026.1.13757, 2025.3.148033, 2025.2.148048, 2025.1.148120, 2024.3.148430, and 2024.2.148429, an authentication bypass via direct database access was possible, leading to administrative access.
- CVE-2026-103494Medium
In JetBrains YouTrack before 2026.2.19422, privilege escalation was possible via user group membership changes.
- CVE-2026-103490High
In JetBrains YouTrack before 2026.2.19422, privilege escalation was possible via user group links. The vulnerability allows a user to gain higher privileges than intended.
Original NVD description (English source)
In JetBrains YouTrack before 2026.2.18991 stored HTML injection via the User-Agent header was possible
Vulnerability data from NVD (NIST) · CISA KEV · EPSS