CVE-2026-9227

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.

CVSS v3.1 Score

8.8

HIGH

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0066

Probability of exploitation

0.47%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-434 Unrestricted Upload

References

Other References

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

Frequently Asked Questions

What is CVE-2026-9227? +

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. It has a CVSS v3.1 base score of 8.8 (HIGH).

How severe is CVE-2026-9227? +

CVE-2026-9227 has a CVSS v3.1 score of 8.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0066, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-9227? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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