Winter CMS up to 1.2.12 FileUpload form widget getFileRecord file_id access control

Summaryinfo

A vulnerability marked as critical has been reported in Winter CMS up to 1.2.12. Impacted is the function getFileRecord of the component FileUpload form widget. This manipulation of the argument file_id causes access control. This vulnerability is tracked as CVE-2026-54256. The attack is possible to be carried out remotely. No exploit exists.

Detailsinfo

A vulnerability was found in Winter CMS up to 1.2.12. It has been declared as critical. Affected by this vulnerability is the function getFileRecord of the component FileUpload form widget. The manipulation of the argument file_id with an unknown input leads to a access control vulnerability. The CWE definition for the vulnerability is CWE-284. The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

Winter CMS is a content management system built on the Laravel PHP framework. In versions up to and including 1.2.12, the backend FileUpload form widget trusted an attacker-controlled file_id POST parameter when resolving the attachment it operates on, allowing an authenticated backend user to read and modify attachment records belonging to other users or records. The widget's getFileRecord() lookup resolved the posted id against the global system_files table without verifying that the file belonged to the widget's own relation, parent record, or deferred-binding session. Because all attachments share a single File model and table and attachment ids are sequential integers that are easily enumerated, a user reaching any form with a fileupload field, including the built-in My Account avatar field that requires no specific permission, could target arbitrary attachments to modify their title and description via onSaveAttachmentConfig and change their sort order via onSortAttachments, which passed posted ids straight to an unscoped update. CSRF tokens remain enforced, so exploitation requires a valid authenticated backend session with any level of access. This issue is fixed in version 1.2.13.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-54256 since 06/12/2026. The exploitation appears to be easy. The attack can be launched remotely. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1068 for this issue.

Upgrading to version 1.2.13 eliminates this vulnerability.

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Productinfo

Type

• Content Management System

Name

• Winter CMS

Version

• 1.2.0
• 1.2.1
• 1.2.2
• 1.2.3
• 1.2.4
• 1.2.5
• 1.2.6
• 1.2.7
• 1.2.8
• 1.2.9
• 1.2.10
• 1.2.11
• 1.2.12

CPE 2.3info

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CPE 2.2info

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