CVE-2026-56385

Medium

Description

Craft CMS versions >= 5.0.0-RC1, <= 5.9.13 and >= 4.0.0-RC1, <= 4.17.7 contain an authorization bypass in the assets/preview-file endpoint. The action does not enforce per-asset view authorization before returning preview content, allowing an authenticated low-privileged user to supply a controlled assetId for an asset they are not permitted to view and still receive preview response data (previewHtml), including a private preview image route containing the target private assetId. Fixed in 5.9.14 and 4.17.8.

SeverityMedium

CVSS4.3

Exploit probability—

ProductCraftcms/cms

PublishedJun 21, 2026

First seenJun 21, 2026

Weakness typeCWE-639Authorization bypass through user-controlled key

How to fix

Update

craftcms/cms5.9.14, 4.17.8 or later

Patches

github.com/craftcms/cms/commit/d30df3112220db1ffd6726a3ed11857014c7fb27

Vendor advisories

github.com/craftcms/cms/security/advisories/GHSA-44px-qjjc-xrhq

Affected products

Product	Affected versions	Fixed in
craftcms/cmsPackagist	5.0.0-RC1 ≤ v < 5.9.14, 4.0.0-RC1 ≤ v < 4.17.8	5.9.14, 4.17.8

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