CVE-2026-56385
Craft CMS: Authorized asset "preview file" requests bypass allows users without asset access to retrieve private preview metadata
Description
### 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
How to fix CVE-2026-56385
To remediate CVE-2026-56385, upgrade the affected package to a fixed version below.
- —upgrade to 5.9.14 or later
Is CVE-2026-56385 being exploited?
Low — EPSS is 0.2%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- >= 5.0.0-RC1, < 5.9.14
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U |