CVE-2026-18488

The Blocksy Companion plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'tagName' Block Attribute (blocksy/dynamic-data) in all versions up to, and including, 2.1.51 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with author-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

  • Published Sep 1, 2026
  • CVSS 6.4 medium
  • 0.3% chance of exploitation in the next 30 days (EPSS)
  • A fix is available

Affected software

CVE-2026-18488 at the National Vulnerability Database