CVE-2026-50281
Craft CMS: Mass assignment via id in newAttributes during bulk duplicate overwrites existing elements
Description
Craft CMS is a content management system (CMS). Versions 5.7.0 and above, prior to 5.9.21 contain a mass-assignment flaw in the bulk-duplicate element action. An attacker who is only able to duplicate their own entires can submit an arbitrary id through the newAttributes request parameter. The duplication routine overrides its own id = null reset with that value and writes the attacker's attributes into the victim's existing entry row. ElementsController::beforeAction() pulls the request body into $this->_attributes and rejects requests that ship an id or canonicalId key at the top level, actionBulkDuplicate(), reads a separate newAttributes array and passes it straight through to the service layer. Elements::duplicateElement() clones the source element, sets id to null, and then hands the attacker's array to Craft::configure(), which overwrites the reset id with any numeric value inside $newAttributes. PHP Yii's saveElement() then performs an UPDATE against the row with that primary key instead of an INSERT. The attackers's title, slug, authorId, postDate, and UID land on the victim's entry. safeAttributes() on Entry includes id because the base element model exposes it, so the Collection::only() filter does not strip it. This issue has been fixed in version 5.9.21.
INFO
Published Date :
July 2, 2026, 5:17 p.m.
Last Modified :
Oct. 25, 2026, 9:10 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Update Craft CMS to version 5.9.21 or later.
- Review and apply vendor patches if applicable.
- Validate element duplication functionality.
- Monitor for unauthorized attribute changes.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-50281.
| URL | Resource |
|---|---|
| https://github.com/craftcms/cms/commit/8f6587c25050bbb6e080d59c71f6bb8932fc8600 | |
| https://github.com/craftcms/cms/security/advisories/GHSA-x5m4-g2cq-52pq |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-50281 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-50281
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-50281 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-50281 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Translated by [email protected]
Oct. 25, 2026
Action Type Old Value New Value Added Translation Title: cms de craftcms, Description: Craft CMS es un sistema de gestión de contenido (CMS). Las versiones 5.7.0 y superiores, anteriores a la 5.9.21, contienen una falla de asignación masiva en la acción de elemento de duplicación masiva. Un atacante que solo puede duplicar sus propias entradas puede enviar un ID arbitrario a través del parámetro de solicitud newAttributes. La rutina de duplicación anula su propio restablecimiento de id = null con ese valor y escribe los atributos del atacante en la fila de entrada existente de la víctima. ElementsController::beforeAction() extrae el cuerpo de la solicitud en $this -> _attributes y rechaza las solicitudes que envían una clave id o canonicalId en el nivel superior, actionBulkDuplicate(), lee un array newAttributes separado y lo pasa directamente a la capa de servicio. Elements::duplicateElement() clona el elemento de origen, establece id en null y luego entrega el array del atacante a Craft::configure(), que sobrescribe el id restablecido con cualquier valor numérico dentro de $newAttributes. El saveElement() de PHP Yii luego realiza un UPDATE contra la fila con esa clave primaria en lugar de un INSERT. El título, slug, authorId, postDate y UID del atacante terminan en la entrada de la víctima. safeAttributes() en Entry incluye id porque el modelo de elemento base lo expone, por lo que el filtro Collection::only() no lo elimina. Este problema ha sido solucionado en la versión 5.9.21. -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 02, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-50281', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-02T19:33:59.852902Z'} -
New CVE Received by [email protected]
Jul. 02, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'craftcms', 'product': 'cms', 'versions': [{'status': 'affected', 'version': '>= 5.7.0, < 5.9.21'}]}] Added Description Craft CMS is a content management system (CMS). Versions 5.7.0 and above, prior to 5.9.21 contain a mass-assignment flaw in the bulk-duplicate element action. An attacker who is only able to duplicate their own entires can submit an arbitrary id through the newAttributes request parameter. The duplication routine overrides its own id = null reset with that value and writes the attacker's attributes into the victim's existing entry row. ElementsController::beforeAction() pulls the request body into $this->_attributes and rejects requests that ship an id or canonicalId key at the top level, actionBulkDuplicate(), reads a separate newAttributes array and passes it straight through to the service layer. Elements::duplicateElement() clones the source element, sets id to null, and then hands the attacker's array to Craft::configure(), which overwrites the reset id with any numeric value inside $newAttributes. PHP Yii's saveElement() then performs an UPDATE against the row with that primary key instead of an INSERT. The attackers's title, slug, authorId, postDate, and UID land on the victim's entry. safeAttributes() on Entry includes id because the base element model exposes it, so the Collection::only() filter does not strip it. This issue has been fixed in version 5.9.21. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-915 Added Reference https://github.com/craftcms/cms/commit/8f6587c25050bbb6e080d59c71f6bb8932fc8600 Added Reference https://github.com/craftcms/cms/security/advisories/GHSA-x5m4-g2cq-52pq