EUVD-2026-21658
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Lifecycle Timeline
3Description
The BuddyPress Groupblog plugin for WordPress is vulnerable to Privilege Escalation in all versions up to, and including, 1.9.3. This is due to the group blog settings handler accepting the `groupblog-blogid`, `default-member`, and `groupblog-silent-add` parameters from user input without proper authorization checks. The `groupblog-blogid` parameter allows any group admin (including Subscribers who create their own group) to associate their group with any blog on the Multisite network, including the main site (blog ID 1). The `default-member` parameter accepts any WordPress role, including `administrator`, without validation against a whitelist. When combined with `groupblog-silent-add`, any user who joins the attacker's group is automatically added to the targeted blog with the injected role. This makes it possible for authenticated attackers, with Subscriber-level access and above, to escalate any user (including themselves via a second account) to Administrator on the main site of the Multisite network.
Analysis
Privilege escalation in BuddyPress Groupblog (WordPress plugin) allows authenticated attackers with Subscriber-level access to grant Administrator privileges on any blog in a Multisite network, including the main site. Exploitation leverages missing authorization checks in group blog settings handlers, enabling attackers to inject arbitrary WordPress roles (including administrator) and associate groups with any blog ID. …
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Remediation
Within 24 hours: Identify all WordPress Multisite installations with BuddyPress Groupblog enabled using plugin audit tools; document the installed version and number of Subscriber-level users with network access. Within 7 days: Immediately disable or deactivate the BuddyPress Groupblog plugin across all affected Multisite networks; audit user roles on all blogs for unauthorized Administrator accounts added post-plugin deployment; reset credentials for all Subscriber accounts. …
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External POC / Exploit Code
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