# CVE-2026-11976: MonsterInsights Pro 10.2.0/10.2.2 - Backdoored via AWS S3 bucket compromise

> Attackers compromised the official update distribution bucket to inject malicious code into MonsterInsights Pro, enabling remote code execution on affected sites.

- **Severity:** Critical 10.0 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 6 Aug 2026
- **Updated:** 7 Aug 2026
- **Also known as:** GHSA-w2mq-7hp5-vcv5

## What is CVE-2026-11976?

CVE-2026-11976 is a critical vulnerability in Unknown MonsterInsights Pro, published on 6 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-912 (Hidden Functionality)

## Which versions are affected by CVE-2026-11976?


## How do I fix CVE-2026-11976?

No fix has been published for CVE-2026-11976 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-11976 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-11976 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-11976 and fix it if it is affected.

What it is: CVE-2026-11976 is a critical vulnerability in Unknown MonsterInsights Pro, published on 6 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-11976 exists.

Affected product: Unknown MonsterInsights Pro. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-11976/ (Markdown: https://insights.sbomify.com/CVE-2026-11976/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-11976
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-11976
- OSV: https://osv.dev/vulnerability/CVE-2026-11976

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-11976/
Summaries are generated and may contain mistakes; the official description above is the record.