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.
History

Tue, 09 Jun 2026 07:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-79

Tue, 09 Jun 2026 06:15:00 +0000

Type Values Removed Values Added
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.
Title Lazy Blocks < 4.3.0 - Admin+ Stored XSS via Custom Block Frontend HTML
References

cve-icon MITRE

Status: PUBLISHED

Assigner: WPScan

Published:

Updated: 2026-06-09T06:00:09.486Z

Reserved: 2026-05-19T13:11:53.990Z

Link: CVE-2026-8981

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-06-09T06:16:54.067

Modified: 2026-06-09T06:16:54.067

Link: CVE-2026-8981

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-06-09T07:30:26Z