Groups – Memberships and Access Control に脆弱性 — CVE-2026-77203
いま何をすべきか
Groups – Memberships and Access Control を 4.7.0 以降に更新してください。
影響を受けるバージョン
- 4.6.0 以下のすべて
対象: プラグイン「Groups – Memberships and Access Control」(groups)
何が起きるのか
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.
ここから先の選択肢
1. 自分たちで対応する
更新の手順、バックアップの取り方、壊れたときの戻し方をまとめています。
2. いまの制作会社・保守業者に頼む
Groups – Memberships and Access Control を使っているかどうかを含めて確認を依頼してください。 無料診断を実行すると、そのまま渡せる依頼文を作れます。
3. 相談先がない・自分では難しい
連絡が取れる相手がいない、管理画面に入れない、侵入された疑いがある。 そうした場合はご相談ください。
出典
- https://plugins.trac.wordpress.org/browser/groups/tags/4.5.0/lib/views/class-groups-shortcodes.php#L463
- https://plugins.trac.wordpress.org/browser/groups/tags/4.5.0/lib/views/class-groups-shortcodes.php#L521
- https://plugins.trac.wordpress.org/browser/groups/tags/4.5.0/lib/views/class-groups-shortcodes.php#L586
- https://plugins.trac.wordpress.org/browser/groups/tags/4.5.0/lib/views/class-groups-shortcodes.php#L624
- https://plugins.trac.wordpress.org/browser/groups/tags/4.5.0/lib/wp/class-groups-wordpress.php#L248
- https://plugins.trac.wordpress.org/changeset/3693123/groups