What’s Vulnerable › Vulnerabilities

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

• Severity: medium (CVSS 6.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-04-18 · updated 2026-06-17
• Weakness: CWE-79

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.

Affected products

• vanderwijk Content Blocks (Custom Post Widget): through 3.3.9

References

• https://plugins.trac.wordpress.org/changeset/3447914/custom-post-widget
• https://www.wordfence.com/threat-intel/vulnerabilities/id/246dee15-82e0-4630-8d95-d2419e9eaef8?source=cve

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