CVE-2026-9601
Stackable <= 3.19.9 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'save' Parameter
CVSS Score
6.4
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-79 |
| Vendor | bfintal |
| Product | stackable – page builder gutenberg blocks |
| Published | Nov 7, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability
Affected Versions
bfintal / Stackable – Page Builder Gutenberg Blocks
0 ≤ 3.19.9
References
wordfence.com: https://www.wordfence.com/threat-intel/vulnerabilities/id/1d4da874-23c8-4df4-b776-6046ce8d705a?source=cve plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/browser/stackable-ultimate-gutenberg-blocks/tags/3.19.6/src/deprecated/block-defaults/custom-block-styles.php#L223 plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/browser/stackable-ultimate-gutenberg-blocks/tags/3.19.8/src/deprecated/block-defaults/custom-block-styles.php#L223 plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/browser/stackable-ultimate-gutenberg-blocks/tags/3.19.8/src/deprecated/block-defaults/custom-block-styles.php#L181 plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/browser/stackable-ultimate-gutenberg-blocks/tags/3.19.8/src/deprecated/block-defaults/custom-block-styles.php#L155 plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/browser/stackable-ultimate-gutenberg-blocks/tags/3.19.8/src/deprecated/block-defaults/custom-block-styles.php#L432 plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/browser/stackable-ultimate-gutenberg-blocks/tags/3.19.6/src/deprecated/block-defaults/custom-block-styles.php#L181 plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/browser/stackable-ultimate-gutenberg-blocks/tags/3.19.6/src/deprecated/block-defaults/custom-block-styles.php#L155 plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/browser/stackable-ultimate-gutenberg-blocks/tags/3.19.6/src/deprecated/block-defaults/custom-block-styles.php#L432 github.com: https://github.com/gambitph/Stackable/pull/3725 plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/changeset/3609541/stackable-ultimate-gutenberg-blocks/trunk/src/deprecated/block-defaults/custom-block-styles.php
Credits
Osvaldo Noe Gonzalez Del Rio (Os)