What’s Vulnerable › Vulnerabilities
CVE-2026-11976: MonsterInsights Pro 10.2.0/10.2.2 - Backdoored via AWS S3 bucket compromise
- Severity: critical (CVSS 10.0 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.5% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-08-06 · updated 2026-08-26
- Weakness: CWE-912
Description
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.
Affected products
- MonsterInsights Pro: from 10.2.0 before 11.0.0 — fixed in 11.0.0
How to fix
Upgrade to a fixed version: MonsterInsights Pro 11.0.0. Check the vendor advisory for mitigations.
References
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