CVE-2021-39203: Private data disclosure/privilege escalation through the block editor in Wordpress

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.9% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-09-09 · updated 2026-06-17
Weakness: CWE-200

Description

WordPress is a free and open-source content management system written in PHP and paired with a MySQL or MariaDB database. In affected versions authenticated users who don't have permission to view private post types/data can bypass restrictions in the block editor under certain conditions. This affected WordPress 5.8 beta during the testing period. It's fixed in the final 5.8 release.

Affected products

WordPress: 5.8-beta1

References

https://github.com/WordPress/wordpress-develop/security/advisories/GHSA-qxvw-qxm9-qvg6
https://hackerone.com/reports/1225282
https://github.com/WordPress/wordpress-develop/security/advisories/GHSA-qxvw-qxm9-qvg6
https://hackerone.com/reports/1225282

Get alerted when CVE-2021-39203 or the next vulnerability affects your stack