What is CVE-2026-77820?

CVE-2026-77820 is a medium-severity vulnerability in Stellarwp Wpcomplete, classified under Cross-site Scripting. CVSS score: 6.4/10. Published 2026-09-19.

How severe is CVE-2026-77820?

Medium severity. CVSS v3 base score is 6.4 out of 10.

XSS in Stellarwp Wpcomplete

CVE-2026-77820

The WPComplete plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'empty' Shortcode Attribute in all versions up to, and including, 2.9.9.0 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This requires the premium version of the software in order to exploit. Please note this only affects the pro version.

Vulnerability class: XSS (Cross-Site Scripting)

CVSS v3 metric

CVSS v3 base score 6.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N.

Affected products

Stellarwp Wpcomplete

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

Frequently asked questions

What is CVE-2026-77820?: CVE-2026-77820 is a medium-severity vulnerability in Stellarwp Wpcomplete, classified under Cross-site Scripting. CVSS score: 6.4/10. Published 2026-09-19.
How severe is CVE-2026-77820?: Medium severity. CVSS v3 base score is 6.4 out of 10.