CVE-2026-9601

Stackable <= 3.19.9 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'save' Parameter

Published Nov 7, 2026 CVSS 3.1 · 6.4 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
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
Type Values Removed Values Added
Metrics ssvc

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

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'}

Subscriptions

No data.

Weaknesses

Sources

Status
PUBLISHED
Assigner
Wordfence
Published
Updated
Nov 7, 2026, 6:06 PM
Reserved
May 26, 2026, 3:34 PM
Status
Deferred
Published
Nov 7, 2026, 5:19 AM
Modified
Nov 7, 2026, 6:17 PM