# CVE-2026-9227: GutenBee <= 2.20.1 - Authenticated (Author+) Arbitrary File Upload via wp_check_filetype_and_ext Filter

> Authenticated attackers with author privileges can upload executable files via double-extension bypass, leading to remote code execution.

- **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 28 May 2026
- **Updated:** 28 May 2026
- **Also known as:** GHSA-fxjg-wrwj-m45j

## What is CVE-2026-9227?

CVE-2026-9227 is a high-severity vulnerability in cssigniterteam GutenBee – Gutenberg Blocks, published on 28 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

The GutenBee – Gutenberg Blocks plugin for WordPress is vulnerable to Arbitrary File Upload in all versions up to, and including, 2.20.1 via the gutenbee_file_and_ext_json function. This is due to a flawed strpos() substring check that only verifies whether the filename contains the string '.json' rather than confirming the filename ends with a .json extension, allowing double-extension filenames like shell.json.php to bypass validation. This makes it possible for authenticated attackers, with author-level access and above, to upload files that may be executable, which makes remote code execution possible.

Weakness: CWE-434 (Unrestricted Upload of File with Dangerous Type)

## Which versions are affected by CVE-2026-9227?


## How do I fix CVE-2026-9227?

No fix has been published for CVE-2026-9227 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-9227 being exploited?

There is no known exploitation of CVE-2026-9227 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-9227 and fix it if it is affected.

What it is: CVE-2026-9227 is a high-severity vulnerability in cssigniterteam GutenBee – Gutenberg Blocks, published on 28 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-9227 in the wild and no public exploit code.

Affected product: cssigniterteam GutenBee – Gutenberg Blocks. 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-2026-9227/ (Markdown: https://insights.sbomify.com/CVE-2026-9227/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-9227
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-9227
- OSV: https://osv.dev/vulnerability/CVE-2026-9227

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-9227/
Summaries are generated and may contain mistakes; the official description above is the record.