CVE-2026-100263

In JetBrains YouTrack before 2026.2.18991 stored HTML injection via the User-Agent header was possible

Published Sep 30, 2026
CVSS 6.1 medium
0.2% chance of exploitation in the next 30 days (EPSS)
A fix is available

Affected software

JetBrains YouTrack

CVE-2026-100263 at the National Vulnerability Database