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OpenAdvisories
Low · 3.5 CVE-2026-8981 EUVD-2026-35352GHSA-cfcv-65jq-76jw

Lazy Blocks < 4.3.0 - Admin+ Stored XSS via Custom Block Frontend HTML

Published Jun 9, 2026 · Updated Jun 9, 2026 · Assigned by WPScan

Description

The Custom Block Builder WordPress plugin before 4.3.0 does not consistently check the unfiltered_html capability across all paths that write to its block template code fields, allowing administrators on multisite installations (or single-site installs with DISALLOW_UNFILTERED_HTML defined) to inject arbitrary JavaScript that executes for any visitor of pages embedding the affected block.

Affected products

VendorProductAffectedFixed
— Custom Block Builder < 4.3.0 4.3.0

References