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.
History

Fri, 29 May 2026 16:00:00 +0000

Type Values Removed Values Added
First Time appeared Cssigniterteam
Cssigniterteam gutenbee – Gutenberg Blocks
Wordpress
Wordpress wordpress
Vendors & Products Cssigniterteam
Cssigniterteam gutenbee – Gutenberg Blocks
Wordpress
Wordpress wordpress

Thu, 28 May 2026 11:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Thu, 28 May 2026 07:30:00 +0000

Type Values Removed Values Added
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.
Title GutenBee <= 2.20.1 - Authenticated (Author+) Arbitrary File Upload via wp_check_filetype_and_ext Filter
Weaknesses CWE-434
References
Metrics cvssV3_1

{'score': 8.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: Wordfence

Published: 2026-05-28T06:45:39.874Z

Updated: 2026-05-28T10:35:06.797Z

Reserved: 2026-05-21T18:32:17.661Z

Link: CVE-2026-9227

cve-icon Vulnrichment

Updated: 2026-05-28T10:35:00.545Z

cve-icon NVD

Status : Deferred

Published: 2026-05-28T08:16:37.713

Modified: 2026-05-28T13:45:25.260

Link: CVE-2026-9227

cve-icon Redhat

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