{"id":"CVE-2026-77203","state":"PUBLISHED","title":"Groups <= 4.6.0 - Authenticated (Subscriber+) Privilege Escalation via 'groups_join' Shortcode","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.","publishedAt":"2026-09-26T17:28:59.609Z","updatedAt":"2026-09-26T22:51:17.071Z","severity":{"score":8.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Wordfence"},"assigner":"Wordfence","products":["itthinx Groups – Memberships and Access Control"],"affected":[{"vendor":"itthinx","product":"Groups – Memberships and Access Control","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThanOrEqual":"4.6.0","versionType":"semver"}]}],"references":["https://www.wordfence.com/threat-intel/vulnerabilities/id/e86dddc9-c1d3-426b-8ec7-2e56dc3c2379?source=cve","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/views/class-groups-shortcodes.php#L463","https://plugins.trac.wordpress.org/browser/groups/tags/4.5.0/lib/wp/class-groups-wordpress.php#L248","https://plugins.trac.wordpress.org/browser/groups/tags/4.5.0/lib/views/class-groups-shortcodes.php#L521","https://plugins.trac.wordpress.org/changeset/3693123/groups"],"weaknesses":["CWE-269"],"ingestedAt":"2026-10-29T20:13:07.220Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/77xxx/CVE-2026-77203.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-77203","state":"PUBLISHED","datePublished":"2026-09-26T17:28:59.609Z","dateUpdated":"2026-09-26T22:51:17.071Z","assignerShortName":"Wordfence","assignerOrgId":"b15e7b5b-3da4-40ae-a43c-f7aa60e62599","dateReserved":"2026-08-20T18:03:15.864Z"},"containers":{"cna":{"title":"Groups <= 4.6.0 - Authenticated (Subscriber+) Privilege Escalation via 'groups_join' Shortcode","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"itthinx","product":"Groups – Memberships and Access Control","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThanOrEqual":"4.6.0","versionType":"semver"}]}],"references":[{"url":"https://www.wordfence.com/threat-intel/vulnerabilities/id/e86dddc9-c1d3-426b-8ec7-2e56dc3c2379?source=cve"},{"url":"https://plugins.trac.wordpress.org/browser/groups/tags/4.5.0/lib/views/class-groups-shortcodes.php#L586"},{"url":"https://plugins.trac.wordpress.org/browser/groups/tags/4.5.0/lib/views/class-groups-shortcodes.php#L624"},{"url":"https://plugins.trac.wordpress.org/browser/groups/tags/4.5.0/lib/views/class-groups-shortcodes.php#L463"},{"url":"https://plugins.trac.wordpress.org/browser/groups/tags/4.5.0/lib/wp/class-groups-wordpress.php#L248"},{"url":"https://plugins.trac.wordpress.org/browser/groups/tags/4.5.0/lib/views/class-groups-shortcodes.php#L521"},{"url":"https://plugins.trac.wordpress.org/changeset/3693123/groups"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":8.8,"baseSeverity":"HIGH"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-269","lang":"en","description":"CWE-269 Improper Privilege Management","type":"CWE"}]}],"providerMetadata":{"shortName":"Wordfence","orgId":"b15e7b5b-3da4-40ae-a43c-f7aa60e62599","dateUpdated":"2026-09-26T17:28:59.609Z"},"credits":[{"lang":"en","type":"finder","value":"daroo"}],"timeline":[{"time":"2026-09-26T04:34:00.000Z","lang":"en","value":"Disclosed"}]},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-77203","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-09-26T22:44:23.567859Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-26T22:51:17.071Z"}}]}}}