GHSA-86VW-X4WW-X467
Vulnerability from github – Published: 2026-07-09 13:44 – Updated: 2026-08-06 21:41The actionRenderCardPreview() method in FieldsController passes the fieldLayoutConfig POST parameter directly to Fields::createLayout() without calling Component::cleanseConfig(). This allows Yii2 event handler injection via on eventName keys in the config array, leading to arbitrary code execution.
This is the same vulnerability pattern that was fixed in GHSA-4484-8v2f-5748 (same file, _fldComponent method correctly uses cleanseConfig), GHSA-qx2q-q59v-wf3j (EntryTypesController), and GHSA-2fph-6v5w-89hh (ElementIndexesController).
PoC
As an admin user with a valid session:
POST /admin/actions/fields/render-card-preview HTTP/1.1
Content-Type: application/x-www-form-urlencoded
Cookie: CraftSessionId=<session>
fieldLayoutConfig[on+init]=phpinfo&CRAFT_CSRF_TOKEN=<token>
When the FieldLayout object is constructed, Yii2 processes the on init key as an event handler registration. During Component::init(), the init event is triggered, calling phpinfo(). The phpinfo output (which includes environment variables, potentially containing database credentials and CRAFT_SECURITY_KEY) will appear in the response.
Impact
An authenticated admin can achieve RCE through Yii2 event handler injection. While this requires admin access (same as GHSA-4484-8v2f-5748, which was rated moderate), it allows arbitrary PHP function execution and information disclosure via phpinfo.
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 5.9.13"
},
"package": {
"ecosystem": "Packagist",
"name": "craftcms/cms"
},
"ranges": [
{
"events": [
{
"introduced": "5.5.0"
},
{
"fixed": "5.9.14"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-56382"
],
"database_specific": {
"cwe_ids": [
"CWE-94"
],
"github_reviewed": true,
"github_reviewed_at": "2026-07-09T13:44:12Z",
"nvd_published_at": null,
"severity": "HIGH"
},
"details": "The `actionRenderCardPreview()` method in `FieldsController` passes the `fieldLayoutConfig` POST parameter directly to `Fields::createLayout()` without calling `Component::cleanseConfig()`. This allows Yii2 event handler injection via `on eventName` keys in the config array, leading to arbitrary code execution.\n\nThis is the same vulnerability pattern that was fixed in GHSA-4484-8v2f-5748 (same file, `_fldComponent` method correctly uses `cleanseConfig`), GHSA-qx2q-q59v-wf3j (EntryTypesController), and GHSA-2fph-6v5w-89hh (ElementIndexesController).\n\n## PoC\n\nAs an admin user with a valid session:\n\n```\nPOST /admin/actions/fields/render-card-preview HTTP/1.1\nContent-Type: application/x-www-form-urlencoded\nCookie: CraftSessionId=\u003csession\u003e\n\nfieldLayoutConfig[on+init]=phpinfo\u0026CRAFT_CSRF_TOKEN=\u003ctoken\u003e\n```\n\nWhen the FieldLayout object is constructed, Yii2 processes the `on init` key as an event handler registration. During `Component::init()`, the `init` event is triggered, calling `phpinfo()`. The phpinfo output (which includes environment variables, potentially containing database credentials and `CRAFT_SECURITY_KEY`) will appear in the response.\n\n## Impact\n\nAn authenticated admin can achieve RCE through Yii2 event handler injection. While this requires admin access (same as GHSA-4484-8v2f-5748, which was rated moderate), it allows arbitrary PHP function execution and information disclosure via phpinfo.",
"id": "GHSA-86vw-x4ww-x467",
"modified": "2026-08-06T21:41:24Z",
"published": "2026-07-09T13:44:12Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/craftcms/cms/security/advisories/GHSA-86vw-x4ww-x467"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-56382"
},
{
"type": "PACKAGE",
"url": "https://github.com/craftcms/cms"
},
{
"type": "WEB",
"url": "https://www.vulncheck.com/advisories/craft-cms-remote-code-execution-via-missing-config-sanitization-in-fieldscontroller"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "Craft CMS: RCE via missing cleanseConfig in FieldsController::actionRenderCardPreview"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
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- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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