Craft CMS: Authorized asset "preview file" requests bypass allows users without asset access to retrieve private preview metadata
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
assets/preview-fileaccepts a maliciously controlledassetIdand renders preview output.- The action does not enforce per-asset view authorization prior to returning preview content.
- 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 software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Composer package | craftcms/cms | >= 5.0.0-RC1, < 5.9.14, >= 4.0.0-RC1, < 4.17.8 | 5.9.14, 4.17.8 |
References
- https://github.com/craftcms/cms/security/advisories/GHSA-44px-qjjc-xrhq
- https://nvd.nist.gov/vuln/detail/CVE-2026-56385
- https://github.com/craftcms/cms/commit/b1cddf72c98a66801beb04ea4b07e72182b7b7db
- https://github.com/craftcms/cms/commit/d30df3112220db1ffd6726a3ed11857014c7fb27
- https://github.com/craftcms/cms
- https://www.vulncheck.com/advisories/craft-cms-authorization-bypass-in-assets-preview-file-endpoint
- CVSS vector
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- Weakness (CWE)
CWE-200, CWE-639, CWE-862- Platform
- Composer
- Package
craftcms/cms- Disclosed
- 26.03.2026
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-44px-qjjc-xrhq - CC BY 4.0
Vulnerability history: craftcms/cms
All published vulnerabilities of this package (Composer package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 127
- First → latest
- 07.2021 08.2026
- Without a fix
- 6
- Exploited in attacks
- 4
Severity breakdown
- Critical 9
- High 41
- Medium 65
- Low 12
Disclosures per year
- 2021: 3
- 2022: 22
- 2023: 13
- 2024: 9
- 2025: 6
- 2026: 74
-
Craft CMS: Authorized asset "preview file" requests bypass allows users without asset access to retrieve private preview metadata this entry
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