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.
CVE-2026-12399 is a medium severity with CVSS 4.4 Stored Cross-Site Scripting issue affecting the Plugin Gutenverse – WordPress Blocks, Page Builder & Site Editor. It affects Versions up to 3.8.0 and is fixed in 3.8.1.
Use the related hub and response guides to connect this CVE-2026-12399 report with patch validation, scanner checks, and site hardening work.
Open the grouped hub for related CVEs, affected ranges, severity mix, and patch coverage.
Check access, XML-RPC exposure, backup readiness, and monitoring after patching.
Use containment, evidence capture, remediation, and validation steps when exploit risk is high.
CVE-2026-12399 is tracked for the Plugin Gutenverse – WordPress Blocks, Page Builder & Site Editor as medium severity with CVSS 4.4. The affected range is Versions up to 3.8.0. Update Gutenverse – WordPress Blocks, Page Builder & Site Editor to 3.8.1 or newer where that version is compatible with the site.
Search engines and operators need more than a title. This page exposes the identifier, affected range, patch evidence, and source coverage that make the vulnerability actionable.
This report has a CVE identifier, which makes it suitable for focused search and vulnerability triage workflows.
Affected version data gives operators a concrete comparison point against installed WordPress software.
A fixed version is present, so the page can answer update and remediation intent directly.
External references are available for source validation, advisory review, and incident notes.
Use these checks when converting this record into a patch ticket, incident note, or risk acceptance decision.
Inventory the installed Plugin package and compare its version with Versions up to 3.8.0.
Confirm Gutenverse – WordPress Blocks, Page Builder & Site Editor is updated to 3.8.1 or newer.
Review references and CVSS vector details for exploitability, authentication requirements, and exposure path.
After patching, re-run vulnerability monitoring and keep the related plugin or theme hub under review for follow-up CVEs.
| Software Type | Plugin |
|---|---|
| Software Slug |
gutenverse
View on wordpress.org
|
| CVE | CVE-2026-12399 |
| Patched Versions |
3.8.1
|
| Affected Versions |
Versions up to 3.8.0
|
These internal links group the same WordPress plugin by CVE, issue type, severity, and patch status so operators and search engines can connect the full vulnerability cluster.
Gutenverse – Ultimate WordPress FSE Blocks Addons & Ecosystem <= 3.5.3 - Authenticated (Contributor+) Server-Side Request Forgery via 'imageUrl'
Gutenverse – Ultimate WordPress FSE Blocks Addons & Ecosystem <= 3.5.3 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'separatorIconSVG'
Gutenverse – Ultimate WordPress FSE Blocks Addons & Ecosystem <= 3.4.6 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'imageLoad'
Gutenverse <= 3.1.0 - Authenticated (Contributor+) Stored Cross-Site Scripting via Animated Text and Fun Fact Blocks
Gutenverse <= 2.2.1 - Authenticated (Contributor+) Stored Cross-Site Scripting via countdown Block
Gutenverse <= 1.9.4 - Authenticated (Contributor+) Stored Cross-Site Scripting
Gutenverse <= 1.9.2 - Authenticated (Contributor+) Stored Cross-Site Scripting
Gutenverse <= 1.9.0 - Authenticated (Contributor+) Stored Cross-Site Scripting
This record contains material that is subject to copyright
License: Defiant hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute this software vulnerability information. Any copy of the software vulnerability information you make for such purposes is authorized provided that you include a hyperlink to this vulnerability record and reproduce Defiant's copyright designation and this license in any such copy. Read more
License: CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE®). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy. Read more
