Cross-site scripting in YouTrack - CVE-2026-86491
Published: September 7, 2026
Vulnerability identifier: #VU147348
CSH Severity: Low
CVSS v4: 5.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N]
CVE-ID: CVE-2026-86491
CWE-ID: CWE-79
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to execute arbitrary JavaScript in a user\'s browser.
The vulnerability exists due to stored cross-site scripting in the project and organization icon upload functionality when uploading a crafted icon file. A remote user can upload an icon file containing malicious script to execute arbitrary JavaScript in the browser of a user who views the uploaded icon.
Affected software
YouTrack
How to mitigate CVE-2026-86491
Install security update from vendor's website.
YouTrack - update to 2026.2.18634