CVE-2026-56385
Craft CMS: Authorized asset "preview file" requests bypass allows users without asset access to retrieve private preview metadata
Summary
### Summary An authenticated low-privileged user can call `assets/preview-file` for an asset they are not authorized to view and still receive preview response data (`previewHtml`) for that private asset. The returned preview HTML included a private preview image route containing the target private `assetId`, even though `canView` was `false` for the attacker account. ### Details 1. `assets/preview-file` accepts a maliciously controlled `assetId` and renders preview output. 2. The action does not enforce per-asset view authorization prior to returning preview content. 3. As a result, an authenticated user without asset-view permission can still obtain private preview output. This affects Craft installations with authenticated users of mixed privilege levels with private assets. ### Resources - d30df3112220db1ffd6726a3ed11857014c7fb27 - b1cddf72c98a
Affected packages
| Ecosystem | Package | Affected versions | Fixed versions |
|---|---|---|---|
| Packagist | craftcms/cms | — | 5.9.14, 4.17.8 |
Remediation: Upgrade to 5.9.14 or later.
References
Includes data from the GitHub Advisory Database, licensed under CC-BY 4.0.
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EPSS scores provided by the FIRST.org Exploit Prediction Scoring System.