CVE-2026-0894: Content Blocks (Custom Post Widget) <= 3.3.9 - Authenticated (Author+) Stored Cross-Site Scripting via content_block Shortcode

Published Apr 18, 2026
·
Updated

The Content Blocks (Custom Post Widget) plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's contentblock shortcode in all versions up to, and including, 3.3.9 due to insufficient input sanitization and output escaping on user supplied values consumed from user-created content blocks. 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.

Affected Software

1 affected component
WordPress Content Blocks (Custom Post Widget)<=3.3.9

Event History

Apr 18, 2026
CVE Published
via MITRE·09:26 AM
Data Sourced
via MITRE·09:26 AM
DescriptionSeverityWeakness
Data Sourced
via NVD·10:16 AM
DescriptionSeverityWeakness

Frequently Asked Questions

1

What is the severity of CVE-2026-0894?

CVE-2026-0894 has a medium severity rating due to its potential to allow stored cross-site scripting attacks.

2

How do I fix CVE-2026-0894?

To fix CVE-2026-0894, update the Content Blocks (Custom Post Widget) plugin to version 3.4.0 or later.

3

What is the risk associated with CVE-2026-0894?

The risk associated with CVE-2026-0894 includes the possibility of attackers executing malicious scripts in the context of the user's session.

4

Who is affected by CVE-2026-0894?

CVE-2026-0894 affects all users of the Content Blocks (Custom Post Widget) plugin for WordPress running versions up to 3.3.9.

5

Is user authentication required to exploit CVE-2026-0894?

Yes, CVE-2026-0894 requires user authentication, as it is an authenticated stored cross-site scripting vulnerability.

Contact

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Fortitude Valley,
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