WordPress Core 5.8 beta - Stored Cross-Site Scripting in Custom HTML Block

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE CVE-2021-39202
CVSS 7.6 (High)
Publicly Published September 9, 2021
Last Updated July 8, 2022
Researcher Evan Ricafort


WordPress is a free and open-source content management system written in PHP and paired with a MySQL or MariaDB database. In affected versions the widgets editor introduced in WordPress 5.8 beta 1 has improper handling of HTML input in the Custom HTML feature. This leads to stored XSS in the custom HTML widget. This has been patched in WordPress 5.8. It was only present during the testing/beta phase of WordPress 5.8.



1 affected software package

Software Type Core
Patched? Yes
Remediation Update to version 5.8, or a newer patched version
Affected Versions
  • 5.8 beta 1 - 5.8 beta 1
  • 5.8 beta 2 - 5.8 beta 2
Patched Version
  • 5.8

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