GHSA-xxpx-f366-4xpq
GHSA-xxpx-f366-4xpq is a remote code execution vulnerability in craftcms/cms. O3 Security confirms whether GHSA-xxpx-f366-4xpq is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Craft CMS:Authorization bypass: view-only Categories user can modify category structure via structures/move-element
Blast Radius
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Description
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.
A 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.
Verified 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.
Impact
A 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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | craftcms/cms | ≥ 5.0.0-RC1&&< 5.10.6 | 5.10.6 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for craftcms/cms. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update craftcms/cms to 5.10.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-xxpx-f366-4xpq is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-xxpx-f366-4xpq is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-xxpx-f366-4xpq. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-xxpx-f366-4xpq in your dependencies?
O3 detects GHSA-xxpx-f366-4xpq across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.