CVE-2026-56385: Craft CMS authorization bypass in assets preview-file endpoint

CVE-2026-56385 · Severity: medium · CVSS 4.3 · Published 2026-06-21

Craft CMS, a popular content management system, contains a security flaw where low-privileged users can view metadata and preview information for private files they are not authorized to access. By sending a specific request to the file preview system, an authenticated user can bypass permission checks to see private asset details. This could lead to the unauthorized disclosure of sensitive internal file information or metadata.

Technologies: craftcms/cms (Packagist). Vendors: Packagist.

Quick answers

Is CVE-2026-56385 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-56385 being exploited in the wild.
How severe is CVE-2026-56385?
Medium severity, with a CVSS score of 4.3, published 21 June 2026.
Which products and versions are affected?
craftcms/cms (Packagist) ECOSYSTEM:introduced=5.0.0-RC1,fixed=5.9.14.
Is there a fix for CVE-2026-56385?
Yes. craftcms/cms (Packagist): upgrade to 5.9.14 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-56385 attacked?
It is attacked over the network, in a web application.
Am I affected by CVE-2026-56385?
Check whether you run craftcms/cms (Packagist) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • craftcms/cms (Packagist): upgrade to 5.9.14 or later
    composer require craftcms/cms:^5.9.14

Technical details

An authorization bypass vulnerability exists in Craft CMS within the `assets/preview-file` endpoint. The application fails to enforce per-asset 'view' authorization checks before returning preview content (`previewHtml`). An authenticated attacker with low privileges can provide a maliciously controlled `assetId` to the endpoint to receive preview response data for private assets, even if their `canView` permission is set to false. This results in the exposure of private preview image routes and associated metadata (CWE-862, CWE-639). The issue is resolved in versions 4.17.8 and 5.9.14.

Affected products

  • Pixel & Tonic Craft CMS >= 4.0.0-RC1, <= 4.17.7; >= 5.0.0-RC1, <= 5.9.13

Identifiers

  • CVE-2026-56385
  • GHSA-44px-qjjc-xrhq

Timeline

  • 2026-03-24: disclosed
  • 2026-03-26: advisory
  • 2026-03-26: patched

References

This page as Markdown. Free to reuse under CC BY 4.0 with a link back.