What is CVE-2026-8981?

CVE-2026-8981 is a low-severity vulnerability in Custom Block Builder, classified under Cross-site Scripting. CVSS score: 3.5/10. Published 2026-06-09.

How severe is CVE-2026-8981?

Low severity. CVSS v3 base score is 3.5 out of 10.

XSS in Custom Block Builder

CVE-2026-8981

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…

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.001 (3.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 3.5 (Low). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:N.

Affected products

Unknown Custom Block Builder — versions 0

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

contact@wpscan.com (technical-description, exploit, vdb-entry)

Frequently asked questions

What is CVE-2026-8981?: CVE-2026-8981 is a low-severity vulnerability in Custom Block Builder, classified under Cross-site Scripting. CVSS score: 3.5/10. Published 2026-06-09.
How severe is CVE-2026-8981?: Low severity. CVSS v3 base score is 3.5 out of 10.