Content Blocks (Custom Post Widget): Cross-site scripting
Content Blocks (Custom Post Widget) is affected by cross-site scripting. Exploitation requires at least contributor-level access. Injected script can execute in the affected site's origin when the vulnerable output is viewed. The published affected range is <= 3.3.9.
- Component
- Content Blocks (Custom Post Widget)
- Plugin slug
content-blocks-custom-post-widget- Affected
- <= 3.3.9
- Safe version
> 3.3.9- Published
- Apr 18, 2026
This CVE was published Apr 18, 2026 and is one of 1 known issue for this plugin.
Update, patch or deactivate.
Update Content Blocks (Custom Post Widget) to a release after 3.3.9, or disable and remove it until a fixed version is available.
A safe version is available, so updating to that version or later is the preferred remediation. If an immediate update is not practical, consider a targeted application patch or temporarily restricting the affected functionality.
Deactivate only when warranted by your risk profile, or when advised by your hosting provider in the limited circumstances where the vulnerability cannot otherwise be mitigated. If you’re unsure which action is appropriate, contact Fused or your hosting provider for guidance.
Technical description
The Content Blocks (Custom Post Widget) plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's content_block 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.
CVE / CNA vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N