CVE-2026-54256: medium-severity vulnerability in wintercms winter
Winter: Authenticated IDOR in backend FileUpload widget allows cross-user access to attachment metadata
Published · Updated
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13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 5.4epss 0.2%
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.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
Affected products
wintercms · winterRelated CVEs — wintercms winter
In the same product, most dangerous first.
CVE-2023-52085LOWWinter CMS Local File Inclusion through Server Side Template Injection EPSS 30.2%CVE-2023-37269LOWWinter CMS vulnerable to stored XSS through privileged upload of SVG fileEPSS 2.7%CVE-2022-39357HIGHWinter vulnerable to Prototype Pollution in Snowboard frameworkEPSS 1.4%CVE-2026-79774CRITICALWinter CMS before 1.2.13 Twig Sandbox Escape via SecurityPolicyEPSS 0.8%CVE-2026-27591CRITICALWinter: Privilege escalation by authenticated backend usersEPSS 0.8%CVE-2026-63179MEDIUMWinter: Local File Inclusion through @import directives in LESS compilation of backend customizable stylesheets and theme assetsEPSS 0.5%