The Stackable – Page Builder Gutenberg Blocks plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'update_block_style' endpoint in all versions up to, and including, 3.19.9 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

Metrics

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required Low

Scope Changed

Confidentiality Impact Low

Integrity Impact Low

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Key SSVC decision points have not yet been added.

Affected Vendors & Products

No data.

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References
Link Providers
https://github.com/gambitph/Stackable/pull/3725 cve-icon cve-icon
https://plugins.trac.wordpress.org/browser/stackable-ultimate-gutenberg-blocks/tags/3.19.6/src/deprecated/block-defaults/custom-block-styles.php#L155 cve-icon cve-icon
https://plugins.trac.wordpress.org/browser/stackable-ultimate-gutenberg-blocks/tags/3.19.6/src/deprecated/block-defaults/custom-block-styles.php#L181 cve-icon cve-icon
https://plugins.trac.wordpress.org/browser/stackable-ultimate-gutenberg-blocks/tags/3.19.6/src/deprecated/block-defaults/custom-block-styles.php#L223 cve-icon cve-icon
https://plugins.trac.wordpress.org/browser/stackable-ultimate-gutenberg-blocks/tags/3.19.6/src/deprecated/block-defaults/custom-block-styles.php#L432 cve-icon cve-icon
https://plugins.trac.wordpress.org/browser/stackable-ultimate-gutenberg-blocks/tags/3.19.8/src/deprecated/block-defaults/custom-block-styles.php#L155 cve-icon cve-icon
https://plugins.trac.wordpress.org/browser/stackable-ultimate-gutenberg-blocks/tags/3.19.8/src/deprecated/block-defaults/custom-block-styles.php#L181 cve-icon cve-icon
https://plugins.trac.wordpress.org/browser/stackable-ultimate-gutenberg-blocks/tags/3.19.8/src/deprecated/block-defaults/custom-block-styles.php#L223 cve-icon cve-icon
https://plugins.trac.wordpress.org/browser/stackable-ultimate-gutenberg-blocks/tags/3.19.8/src/deprecated/block-defaults/custom-block-styles.php#L432 cve-icon cve-icon
https://plugins.trac.wordpress.org/changeset/3609541/stackable-ultimate-gutenberg-blocks/trunk/src/deprecated/block-defaults/custom-block-styles.php cve-icon cve-icon
https://www.wordfence.com/threat-intel/vulnerabilities/id/1d4da874-23c8-4df4-b776-6046ce8d705a?source=cve cve-icon cve-icon
History

Sat, 07 Nov 2026 04:45:00 +0000

Type Values Removed Values Added
Description The Stackable – Page Builder Gutenberg Blocks plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'update_block_style' endpoint in all versions up to, and including, 3.19.9 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
Title Stackable <= 3.19.9 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'save' Parameter
Weaknesses CWE-79
References
Metrics cvssV3_1

{'score': 6.4, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N'}
cve-icon MITRE

Status: PUBLISHED

Assigner: Wordfence

Published: 2026-11-07T04:27:12.469Z

Updated: 2026-11-07T04:27:12.469Z

Reserved: 2026-05-26T15:34:01.308Z

Link: CVE-2026-9601

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Deferred

Published: 2026-11-07T05:19:03.353

Modified: 2026-11-07T05:19:03.550

Link: CVE-2026-9601

cve-icon Redhat

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