CVE-2026-9601Cross-site Scripting (XSS)
NVDCVSS scored by security@wordfence.com
Vulnerability Summary
The Stackable β 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.
CVSS v3.1 Base Metrics — Score 6.4 (MEDIUM)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:NAttack VectorNetwork
Attack ComplexityLow
Privileges RequiredLow
User InteractionNone
ScopeChanged
ConfidentialityLow
IntegrityLow
AvailabilityNone
Affected & Patched Versions
Not provided by NVD for this CVE.
No patched version published yet
Until a fix ships, reduce exposure:
- Restrict access to the affected service or interface to trusted networks.
- Disable the affected feature if you do not need it.
- Watch the vendor advisory for a firmware or software update.
What to do
Fix it during your normal patch cycle. No exploitation is confirmed yet.
- Check whether you run the affected product and which version.
- No patched version is listed yet. Limit access to the affected service to trusted networks, and disable the feature if you can.
- Subscribe to the vendor advisory so you learn when a fix ships.
Timeline
- Nov 7, 2026Published
- Nov 7, 2026Record last modified
Score, severity and exploitation changes are tracked from the day Watchtower started logging them.
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Set up CVE alertsExternal References
- Patchhttps://github.com/gambitph/Stackable/pull/3725
- Referencehttps://plugins.trac.wordpress.org/browser/stackable-ultimate-gutenberg-blocks/tags/3.19.6/src/deprecated/block-defaults/custom-block-styles.php#L155
- Referencehttps://plugins.trac.wordpress.org/browser/stackable-ultimate-gutenberg-blocks/tags/3.19.6/src/deprecated/block-defaults/custom-block-styles.php#L181
- Referencehttps://plugins.trac.wordpress.org/browser/stackable-ultimate-gutenberg-blocks/tags/3.19.6/src/deprecated/block-defaults/custom-block-styles.php#L223
- Referencehttps://plugins.trac.wordpress.org/browser/stackable-ultimate-gutenberg-blocks/tags/3.19.6/src/deprecated/block-defaults/custom-block-styles.php#L432
- Referencehttps://plugins.trac.wordpress.org/browser/stackable-ultimate-gutenberg-blocks/tags/3.19.8/src/deprecated/block-defaults/custom-block-styles.php#L155
- Referencehttps://plugins.trac.wordpress.org/browser/stackable-ultimate-gutenberg-blocks/tags/3.19.8/src/deprecated/block-defaults/custom-block-styles.php#L181
- Referencehttps://plugins.trac.wordpress.org/browser/stackable-ultimate-gutenberg-blocks/tags/3.19.8/src/deprecated/block-defaults/custom-block-styles.php#L223
- Referencehttps://plugins.trac.wordpress.org/browser/stackable-ultimate-gutenberg-blocks/tags/3.19.8/src/deprecated/block-defaults/custom-block-styles.php#L432
- Referencehttps://plugins.trac.wordpress.org/changeset/3609541/stackable-ultimate-gutenberg-blocks/trunk/src/deprecated/block-defaults/custom-block-styles.php
- Referencehttps://www.wordfence.com/threat-intel/vulnerabilities/id/1d4da874-23c8-4df4-b776-6046ce8d705a?source=cve
Data last checked: Nov 7, 2026 05:01 UTC