CVE-2026-8981

LOW

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

Title source: cna

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.

References (1)

Core 1

Core References

Exploit exploit vdb-entry technical-description

https://wpscan.com/vulnerability/9815b0e6-e411-4a5c-9c63-30bad21da698/

Scores

CVSS v3 3.5

EPSS 0.0014

EPSS Percentile 3.8%

Attack Vector NETWORK

CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:N

CISA SSVC

Vulnrichment

Exploitation none

Automatable no

Technical Impact partial

Details

CWE

CWE-79

Status published

Products (1)

None/Custom Block Builder < 4.3.0

Published Jun 09, 2026

Tracked Since Jun 09, 2026