FKIE_CVE-2026-77203

Vulnerability from fkie_nvd - Published: 2026-09-26 18:16 - Updated: 2026-09-26 23:16
Severity
8.8 (High) - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Summary
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.
References
security@wordfence.comhttps://plugins.trac.wordpress.org/browser/groups/tags/4.5.0/lib/views/class-groups-shortcodes.php#L463
security@wordfence.comhttps://plugins.trac.wordpress.org/browser/groups/tags/4.5.0/lib/views/class-groups-shortcodes.php#L521
security@wordfence.comhttps://plugins.trac.wordpress.org/browser/groups/tags/4.5.0/lib/views/class-groups-shortcodes.php#L586
security@wordfence.comhttps://plugins.trac.wordpress.org/browser/groups/tags/4.5.0/lib/views/class-groups-shortcodes.php#L624
security@wordfence.comhttps://plugins.trac.wordpress.org/browser/groups/tags/4.5.0/lib/wp/class-groups-wordpress.php#L248
security@wordfence.comhttps://plugins.trac.wordpress.org/changeset/3693123/groups
security@wordfence.comhttps://www.wordfence.com/threat-intel/vulnerabilities/id/e86dddc9-c1d3-426b-8ec7-2e56dc3c2379?source=cve
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Groups \u2013 Memberships and Access Control",
          "vendor": "itthinx",
          "versions": [
            {
              "lessThanOrEqual": "4.6.0",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "source": "security@wordfence.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "The Groups \u2013 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\u0027s author capabilities via the global $post-\u003epost_author rather than from the currently authenticated user\u0027s own capabilities, while simultaneously minting and returning a valid groups-join-data hash and WordPress nonce for the caller in the same response \u2014 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."
    }
  ],
  "id": "CVE-2026-77203",
  "lastModified": "2026-09-26T23:16:35.700",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 8.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 5.9,
        "source": "security@wordfence.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-77203",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-09-26T22:44:23.567859Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-09-26T18:16:29.917",
  "references": [
    {
      "source": "security@wordfence.com",
      "url": "https://plugins.trac.wordpress.org/browser/groups/tags/4.5.0/lib/views/class-groups-shortcodes.php#L463"
    },
    {
      "source": "security@wordfence.com",
      "url": "https://plugins.trac.wordpress.org/browser/groups/tags/4.5.0/lib/views/class-groups-shortcodes.php#L521"
    },
    {
      "source": "security@wordfence.com",
      "url": "https://plugins.trac.wordpress.org/browser/groups/tags/4.5.0/lib/views/class-groups-shortcodes.php#L586"
    },
    {
      "source": "security@wordfence.com",
      "url": "https://plugins.trac.wordpress.org/browser/groups/tags/4.5.0/lib/views/class-groups-shortcodes.php#L624"
    },
    {
      "source": "security@wordfence.com",
      "url": "https://plugins.trac.wordpress.org/browser/groups/tags/4.5.0/lib/wp/class-groups-wordpress.php#L248"
    },
    {
      "source": "security@wordfence.com",
      "url": "https://plugins.trac.wordpress.org/changeset/3693123/groups"
    },
    {
      "source": "security@wordfence.com",
      "url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/e86dddc9-c1d3-426b-8ec7-2e56dc3c2379?source=cve"
    }
  ],
  "sourceIdentifier": "security@wordfence.com",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-269"
        }
      ],
      "source": "security@wordfence.com",
      "type": "Secondary"
    }
  ]
}



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