CVE-2026-77203

Vulnerability Description

The Groups – Memberships and Access Control plugin for WordPress is vulnerable to Privilege Escalation in all versions up to, and including, 4.6.0. This is due to the groups_join() function deriving group-join eligibility from the ambient post's author capabilities via the global $post->post_author rather than from the currently authenticated user's own capabilities, while simultaneously minting and returning a valid groups-join-data hash and WordPress nonce for the caller in the same response — eliminating all authorization barriers to self-enrollment. This makes it possible for authenticated attackers, with Subscriber-level access and above, to enroll themselves into any group including privileged groups carrying the groups_admin_groups capability, and to subsequently create and join a group containing every registered WordPress capability, effectively escalating their privileges to Administrator. Exploitation requires the attacker to supply an Administrator-authored post ID via the post_ID parameter of the authenticated wp_ajax_parse_media_shortcode handler in order to establish the privileged ambient post context used by the flawed authorization check.

CVSS Score

Related Weaknesses (CWE)

References

• https://plugins.trac.wordpress.org/browser/groups/tags/4.5.0/lib/views/class-gro
• https://plugins.trac.wordpress.org/browser/groups/tags/4.5.0/lib/views/class-gro
• https://plugins.trac.wordpress.org/browser/groups/tags/4.5.0/lib/views/class-gro
• https://plugins.trac.wordpress.org/browser/groups/tags/4.5.0/lib/views/class-gro
• https://plugins.trac.wordpress.org/browser/groups/tags/4.5.0/lib/wp/class-groups
• https://plugins.trac.wordpress.org/changeset/3693123/groups
• https://www.wordfence.com/threat-intel/vulnerabilities/id/e86dddc9-c1d3-426b-8ec