CVE-2026-11976

Name of the Vulnerable Software and Affected Versions MonsterInsights Pro versions 10.2.0 through 10.2.2

Description The official update distribution bucket monster-insights.s3.amazonaws.com was compromised, allowing a threat actor to maintain write access and iterate on a malicious payload. This resulted in the inclusion of a malicious file, class-system-check.php, within the software releases. Three distinct variants of the payload were observed, all utilizing the same AES-256-GCM key, which is a symmetric encryption algorithm that provides both confidentiality and authenticity.

Recommendations As a temporary workaround, restrict access to the class-system-check.php file to minimize the risk of exploitation. At the moment, there is no information about a newer version that contains a fix for this vulnerability.