CVE-2026-11976 json
MonsterInsights Pro 10.2.0/10.2.2 - Backdoored via AWS S3 bucket compromise
published 2026-08-06 3 mo ago modified 2026-08-26 2 mo ago also EUVD-2026-54300
- cvss
- 10.0
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.5%
- EPSS 0.5% chance of exploitation in 30 days, percentile 44%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- Unknown MonsterInsights Pro 11.0.0
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- yes
- Technical impact
- total
- Assessed
- 3 mo ago
Exploit prediction
0.52% chance of exploitation in the next 30 days, higher than 44% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- wpscan.com https://wpscan.com/vulnerability/d1250410-b919-4a90-8cf2-04031f9e5e2b/ referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 10.0 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |
Affected products
- Unknown MonsterInsights Pro
Classification
- Weakness
-
- CWE-912 Hidden Functionality
- Technology feeds
References
-
wpscan.com
/vulnerability/d1250410-b919-4a90-8cf2-04031f9e5e2b/
exploit, vdb-entry, technical-description
Sources
- CVE List CVE-2026-11976
- NVD CVE-2026-11976
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.