CVE-2026-12399
Gutenverse <= 3.8.0 - Authenticated (Editor+) Stored Cross-Site Scripting via 'fonts[].font.font.value' Parameter
Description
The Gutenverse – WordPress Blocks, Page Builder & Site Editor plugin for WordPress is vulnerable to Stored Cross-Site Scripting via admin settings in all versions up to, and including, 3.8.0 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with editor-level permissions and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This only affects multi-site installations and installations where unfiltered_html has been disabled.
INFO
Published Date :
June 27, 2026, 8:16 a.m.
Last Modified :
June 29, 2026, 6:40 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | MITRE-CVE | ||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update the Gutenverse plugin to the latest version.
- Apply vendor security patches promptly.
- Review and sanitize all user inputs.
- Ensure proper output escaping is implemented.
Public PoC/Exploit Available at Github
CVE-2026-12399 has a 1 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-12399.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-12399 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-12399
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
None
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-12399 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-12399 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 29, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-12399', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-06-29T12:23:48.294132Z'} -
New CVE Received by [email protected]
Jun. 27, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'jegstudio', 'product': 'Gutenverse – WordPress Blocks, Page Builder & Site Editor', 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'semver', 'lessThanOrEqual': '3.8.0'}], 'defaultStatus': 'unaffected'}] Added Description The Gutenverse – WordPress Blocks, Page Builder & Site Editor plugin for WordPress is vulnerable to Stored Cross-Site Scripting via admin settings in all versions up to, and including, 3.8.0 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with editor-level permissions and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This only affects multi-site installations and installations where unfiltered_html has been disabled. Added CVSS V3.1 AV:N/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:N Added CWE CWE-79 Added Reference https://plugins.trac.wordpress.org/browser/gutenverse/tags/3.6.3/lib/framework/helper.php#L1440 Added Reference https://plugins.trac.wordpress.org/browser/gutenverse/tags/3.6.3/lib/framework/helper.php#L1775 Added Reference https://plugins.trac.wordpress.org/browser/gutenverse/tags/3.6.3/lib/framework/includes/class-api.php#L1956 Added Reference https://plugins.trac.wordpress.org/browser/gutenverse/tags/3.6.3/lib/framework/includes/class-frontend-generator.php#L147 Added Reference https://plugins.trac.wordpress.org/browser/gutenverse/tags/3.6.3/lib/framework/includes/class-global-variable.php#L78 Added Reference https://plugins.trac.wordpress.org/browser/gutenverse/tags/3.8.0/lib/framework/helper.php#L1440 Added Reference https://plugins.trac.wordpress.org/browser/gutenverse/tags/3.8.0/lib/framework/helper.php#L1775 Added Reference https://plugins.trac.wordpress.org/browser/gutenverse/tags/3.8.0/lib/framework/includes/class-api.php#L1956 Added Reference https://plugins.trac.wordpress.org/browser/gutenverse/tags/3.8.0/lib/framework/includes/class-frontend-generator.php#L147 Added Reference https://plugins.trac.wordpress.org/browser/gutenverse/tags/3.8.0/lib/framework/includes/class-global-variable.php#L78 Added Reference https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=3578328%40gutenverse&new=3578328%40gutenverse&sfp_email=&sfph_mail= Added Reference https://www.wordfence.com/threat-intel/vulnerabilities/id/fd1c679b-43e0-4e3a-ae2d-f6ff8a657512?source=cve