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

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.

Published: 2026-05-28 Last update: 2026-05-28 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-9227 is rated Moderate Risk (47.9/100): CVSS High severity, with low exploitation likelihood (EPSS 0.16%). Mandatory action: Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-9227

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-03 0.14% 0.16% +0.02%
2 2026-05-28 0.14%

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-9227

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
2.8 5.9 [email protected]

Weakness enumeration for CVE-2026-9227

GitHub Security Advisory for CVE-2026-9227

GHSA-fxjg-wrwj-m45j · Severity: high — The GutenBee – Gutenberg Blocks plugin for WordPress is vulnerable to Arbitrary File Upload in...

Affected software / configurations for CVE-2026-9227

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-9227

URL Tags
https://github.com/cssigniter/gutenbee/commit/bde934cdecf67a4de1d6548cc1fc6c59bc6690e5
https://plugins.trac.wordpress.org/browser/gutenbee/tags/2.20.0/gutenbee.php#L570
https://plugins.trac.wordpress.org/browser/gutenbee/tags/2.20.0/gutenbee.php#L571
https://plugins.trac.wordpress.org/browser/gutenbee/tags/2.20.0/gutenbee.php#L579
https://plugins.trac.wordpress.org/browser/gutenbee/tags/2.20.1/gutenbee.php#L570
https://plugins.trac.wordpress.org/browser/gutenbee/tags/2.20.1/gutenbee.php#L571
https://plugins.trac.wordpress.org/browser/gutenbee/tags/2.20.1/gutenbee.php#L579
https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=3543574%40gutenbee&new=3543574%40gutenbee&sfp_email=&sfph_mail=
https://www.wordfence.com/threat-intel/vulnerabilities/id/2d20e8c9-975d-4e8c-8bea-50935853c7d4?source=cve
cvelogic Threat Intelligence