CVE-2026-72785: Craft CMS Authorization Bypass: View-only Categories User Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-xxpx-f366-4xpq",
  "modified" : "2026-09-01T21:18:48Z",
  "published" : "2026-08-06T21:43:54Z",
  "aliases" : [ "CVE-2026-72785" ],
  "summary" : "Craft CMS: Authorization bypass: view-only Categories user can modify category structure via structures/move-element",
  "details" : "A control-panel user who holds only the viewCategories permission for a category group (and not saveCategories) can permanently modify that group's category structure — reordering and re-parenting categories via the structures/move-element action.\n\nA read-time authorization grant that a write endpoint later trusts. For categories, the structureEditable flag is computed from the view permission (`src/elements/Category.php:205`) instead of the save permission (entries correctly use saveEntries — `src/elements/Entry.php:341`). When the read-only category index renders, `craft\\base\\Element::indexHtml()` calls `Craft::$app->getSession()->authorize('editStructure:<structureId>');` StructuresController then authorizes the structure-mutating action solely on that session grant, with no canSave re-check.\n\nVerified on Craft CMS 5.10.5. Same class as the moderate-severity authorization bypasses fixed in 5.10.3 and 5.10.5; this is a distinct, unpatched instance.\n\n## Impact\n\nA low-privileged, authenticated user (view-only on a category group) can persistently alter the sibling ordering and parent/child nesting of the category taxonomy. Because a category’s URI is derived from its position in the structure (ancestor slugs), moving a category changes its URL and the URLs of its descendants, and can corrupt any navigation/menus built from the category tree. This is an integrity/broken access-control issue: content that the user has no permission to modify is being modified. No confidentiality impact and no RCE; scope is content/taxonomy integrity.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "craftcms/cms"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "5.0.0-RC1"
      }, {
        "fixed" : "5.10.6"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/craftcms/cms/security/advisories/GHSA-xxpx-f366-4xpq"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-72785"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/craftcms/cms/commit/eb63721b8476ef53f21d7de53d156eef531cb57d"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/craftcms/cms"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/craftcms/cms/releases/tag/4.18.2"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/craftcms/cms/releases/tag/5.10.6"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/craft-cms-before-authorization-bypass-via-structures-move-element"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-863" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-08-06T21:43:54Z",
    "nvd_published_at" : null
  }
}