CVE-2021-27890: Mybb

High severity, CVSS 8.8. EPSS: 10.7% chance of exploitation in the next 30 days.

SQL Injection vulnerablity in MyBB before 1.8.26 via theme properties included in theme XML files.

Affected products

• Mybb Mybb: before 1.8.26 (fixed in 1.8.26)

Published 2021-03-15. Last modified 2026-06-17.