MyBB 1.8.25 - Chained Remote Command Execution

What happened

MyBB XSS and SQL injection chain (CVE-2021-27889/27890) enabling remote code execution.

Affected versions

Unknown product: See original advisory Fixed: See vendor advisory.

Why it matters

This source correlation may provide earlier visibility while structured CVE metadata is still being updated.

Detection & mitigation

• Review the original advisory and validate affected versions.
• Apply vendor-provided updates or mitigations when available.