CVE-2026-11976

The official MonsterInsights Pro update distribution bucket (monster-insights.s3.amazonaws.com) was compromised. Both the current release (10.2.2) and the version MonsterInsights rolled back to (10.2.0) contain a malicious file, class-system-check.php. Three distinct variants were observed on 2026-06-11, all sharing the same AES-256-GCM key, confirming a single threat actor. The attacker retains write access to the S3 bucket and has been actively iterating on the payload throughout the day.