CVE-2026-19807 (GCVE-0-2026-19807)
Vulnerability from cvelistv5
Published
2026-10-01 07:40
Modified
2026-10-03 15:42
Severity ?
8.8 (High) - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE
  • CWE-269 - Improper Privilege Management
Summary
The ByteCoreStack – MCP Connector for AI Tools plugin for WordPress is vulnerable to Privilege Escalation in all versions up to, and including, 1.2.3 This is due to the `wp_update_user_meta` MCP tool in `execute_tool` gating writes solely with `current_user_can('edit_user', $uid)` — a check that WordPress core's `map_meta_cap` resolves to the `read` primitive when the target user ID matches the caller's own — while enforcing an incomplete meta key blocklist that covers only `user_pass`, `user_activation_key`, and `session_tokens`, leaving the `wp_capabilities` and `wp_user_level` meta keys entirely unprotected. This makes it possible for authenticated attackers with Subscriber-level access and above to elevate their privileges to Administrator by issuing a `wp_update_user_meta` call over the MCP JSON-RPC endpoint with `key=wp_capabilities` and an arbitrary role array such as `{'administrator': true}` targeting their own user ID, causing WordPress to load that account as an Administrator on the next request.
References
Impacted products
Vendor Product Version
bytecorestack ByteCoreStack – MCP Connector for AI Tools Version: 0   ≤ 1.2.3
 Create a notification for this product.
Show details on NVD website

To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-19807",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-10-03T15:35:38.770295Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-10-03T15:42:52.096Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "ByteCoreStack \u2013 MCP Connector for AI Tools",
          "vendor": "bytecorestack",
          "versions": [
            {
              "lessThanOrEqual": "1.2.3",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "D\u00e9cio Brand\u00e3o"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "The ByteCoreStack \u2013 MCP Connector for AI Tools plugin for WordPress is vulnerable to Privilege Escalation in all versions up to, and including, 1.2.3 This is due to the `wp_update_user_meta` MCP tool in `execute_tool` gating writes solely with `current_user_can(\u0027edit_user\u0027, $uid)` \u2014 a check that WordPress core\u0027s `map_meta_cap` resolves to the `read` primitive when the target user ID matches the caller\u0027s own \u2014 while enforcing an incomplete meta key blocklist that covers only `user_pass`, `user_activation_key`, and `session_tokens`, leaving the `wp_capabilities` and `wp_user_level` meta keys entirely unprotected. This makes it possible for authenticated attackers with Subscriber-level access and above to elevate their privileges to Administrator by issuing a `wp_update_user_meta` call over the MCP JSON-RPC endpoint with `key=wp_capabilities` and an arbitrary role array such as `{\u0027administrator\u0027: true}` targeting their own user ID, causing WordPress to load that account as an Administrator on the next request."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 8.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-269",
              "description": "CWE-269 Improper Privilege Management",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-01T07:40:24.252Z",
        "orgId": "b15e7b5b-3da4-40ae-a43c-f7aa60e62599",
        "shortName": "Wordfence"
      },
      "references": [
        {
          "url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/ac09bf3e-49cf-4f11-92ba-d1fbf6f587d7?source=cve"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.2.0/includes/MCP/Server.php#L2046"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.2.0/includes/MCP/Server.php#L2042"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.2.0/includes/MCP/Server.php#L2044"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.2.0/includes/MCP/Server.php#L332"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.2.0/includes/OAuth/Server.php#L122"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.1.0/includes/MCP/Server.php#L2046"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.1.0/includes/MCP/Server.php#L2042"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.1.0/includes/MCP/Server.php#L2044"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.1.0/includes/MCP/Server.php#L332"
        },
        {
          "url": "https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.1.0/includes/OAuth/Server.php#L122"
        },
        {
          "url": "https://plugins.trac.wordpress.org/changeset?reponame=\u0026new=3711909%40bcs-mcp-manager%2Ftags%2F1.2.4\u0026old=3711721%40bcs-mcp-manager%2Ftags%2F1.2.3"
        },
        {
          "url": "https://plugins.trac.wordpress.org/changeset/3711908/bcs-mcp-manager/trunk/includes/MCP/Server.php"
        }
      ],
      "timeline": [
        {
          "lang": "en",
          "time": "2026-09-30T19:31:11.000Z",
          "value": "Disclosed"
        }
      ],
      "title": "ByteCoreStack \u003c= 1.2.3 - Authenticated (Subscriber+) Privilege Escalation via wp_update_user_meta MCP Tool"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "b15e7b5b-3da4-40ae-a43c-f7aa60e62599",
    "assignerShortName": "Wordfence",
    "cveId": "CVE-2026-19807",
    "datePublished": "2026-10-01T07:40:24.252Z",
    "dateReserved": "2026-08-13T21:31:00.532Z",
    "dateUpdated": "2026-10-03T15:42:52.096Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-19807\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"total\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-10-03T15:35:38.770295Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-10-03T15:41:08.654Z\"}}], \"cna\": {\"title\": \"ByteCoreStack \u003c= 1.2.3 - Authenticated (Subscriber+) Privilege Escalation via wp_update_user_meta MCP Tool\", \"credits\": [{\"lang\": \"en\", \"type\": \"finder\", \"value\": \"D\\u00e9cio Brand\\u00e3o\"}], \"metrics\": [{\"cvssV3_1\": {\"version\": \"3.1\", \"baseScore\": 8.8, \"baseSeverity\": \"HIGH\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H\"}}], \"affected\": [{\"vendor\": \"bytecorestack\", \"product\": \"ByteCoreStack \\u2013 MCP Connector for AI Tools\", \"versions\": [{\"status\": \"affected\", \"version\": \"0\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"1.2.3\"}], \"defaultStatus\": \"unaffected\"}], \"timeline\": [{\"lang\": \"en\", \"time\": \"2026-09-30T19:31:11.000Z\", \"value\": \"Disclosed\"}], \"references\": [{\"url\": \"https://www.wordfence.com/threat-intel/vulnerabilities/id/ac09bf3e-49cf-4f11-92ba-d1fbf6f587d7?source=cve\"}, {\"url\": \"https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.2.0/includes/MCP/Server.php#L2046\"}, {\"url\": \"https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.2.0/includes/MCP/Server.php#L2042\"}, {\"url\": \"https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.2.0/includes/MCP/Server.php#L2044\"}, {\"url\": \"https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.2.0/includes/MCP/Server.php#L332\"}, {\"url\": \"https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.2.0/includes/OAuth/Server.php#L122\"}, {\"url\": \"https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.1.0/includes/MCP/Server.php#L2046\"}, {\"url\": \"https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.1.0/includes/MCP/Server.php#L2042\"}, {\"url\": \"https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.1.0/includes/MCP/Server.php#L2044\"}, {\"url\": \"https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.1.0/includes/MCP/Server.php#L332\"}, {\"url\": \"https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.1.0/includes/OAuth/Server.php#L122\"}, {\"url\": \"https://plugins.trac.wordpress.org/changeset?reponame=\u0026new=3711909%40bcs-mcp-manager%2Ftags%2F1.2.4\u0026old=3711721%40bcs-mcp-manager%2Ftags%2F1.2.3\"}, {\"url\": \"https://plugins.trac.wordpress.org/changeset/3711908/bcs-mcp-manager/trunk/includes/MCP/Server.php\"}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"The ByteCoreStack \\u2013 MCP Connector for AI Tools plugin for WordPress is vulnerable to Privilege Escalation in all versions up to, and including, 1.2.3 This is due to the `wp_update_user_meta` MCP tool in `execute_tool` gating writes solely with `current_user_can(\u0027edit_user\u0027, $uid)` \\u2014 a check that WordPress core\u0027s `map_meta_cap` resolves to the `read` primitive when the target user ID matches the caller\u0027s own \\u2014 while enforcing an incomplete meta key blocklist that covers only `user_pass`, `user_activation_key`, and `session_tokens`, leaving the `wp_capabilities` and `wp_user_level` meta keys entirely unprotected. This makes it possible for authenticated attackers with Subscriber-level access and above to elevate their privileges to Administrator by issuing a `wp_update_user_meta` call over the MCP JSON-RPC endpoint with `key=wp_capabilities` and an arbitrary role array such as `{\u0027administrator\u0027: true}` targeting their own user ID, causing WordPress to load that account as an Administrator on the next request.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-269\", \"description\": \"CWE-269 Improper Privilege Management\"}]}], \"providerMetadata\": {\"orgId\": \"b15e7b5b-3da4-40ae-a43c-f7aa60e62599\", \"shortName\": \"Wordfence\", \"dateUpdated\": \"2026-10-01T07:40:24.252Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-19807\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-10-03T15:42:52.096Z\", \"dateReserved\": \"2026-08-13T21:31:00.532Z\", \"assignerOrgId\": \"b15e7b5b-3da4-40ae-a43c-f7aa60e62599\", \"datePublished\": \"2026-10-01T07:40:24.252Z\", \"assignerShortName\": \"Wordfence\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.