CVE-2016-9415: Mybb Merge System

High severity, CVSS 7.5. EPSS: 1.9% chance of exploitation in the next 30 days.

MyBB (aka MyBulletinBoard) before 1.8.8 on Windows and MyBB Merge System before 1.8.8 on Windows allow remote attackers to overwrite arbitrary CSS files via vectors related to "style import."

Affected products

• Mybb Merge System: up to and including 1.8.7
• Mybb Mybb: up to and including 1.8.7

Published 2017-01-31. Last modified 2026-06-17.