CVE-2026-8981
Lazy Blocks < 4.3.0 - Admin+ Stored XSS via Custom Block Frontend HTML
Vexday Risk Score
28Low
SSVC decision (CISA)
Attend
PoC available → attend closely
Exploit maturity
Proof of concept
Public proof of concept exists, but not yet automated.
CVSS 3.5EPSS 0.1%KEV nãoPoC públicaNuclei —Metasploit —Patch —
Lifecycle
09 Jun 2026Published on NVD
Recommendation: Plan a near-term fix — a public PoC already exists.
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.
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:N
Affected products
Unknown · Custom Block Builderpublic PoCs found — 1
cve_referencewpscan.com/vulnerability/9815b0e6-e411-4a5c-9c63-30bad21da698/unverified⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.