CVE-2016-9412: Mybb Merge System

Critical severity, CVSS 9.8. EPSS: 2.2% chance of exploitation in the next 30 days.

MyBB (aka MyBulletinBoard) before 1.8.7 and MyBB Merge System before 1.8.7 allow attackers to have unspecified impact via vectors related to low adminsid and sid entropy.

Affected products

  • Mybb Merge System: up to and including 1.8.6
  • Mybb Mybb: up to and including 1.8.6

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