SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-11976

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`.

CRITICAL 10.0EPSS 0.49%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.49%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1
10.0 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
EPSS
0.49% probability · 40th percentile
CISA KEV
Not listed
Weakness
CWE-912
Source
contact@wpscan.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.