Medium severity4.3NVD Advisory· Published Jun 21, 2026· Updated Jun 24, 2026
CVE-2026-56384
CVE-2026-56384
Description
Craft CMS contains a missing authorization vulnerability in the assets/preview-thumb endpoint. A Control Panel user without permission to view a target private asset can call the endpoint with an attacker-controlled assetId and receive preview HTML containing a signed fallback transform preview link for that private asset, because no asset-view permission check is performed before preview generation. This affects versions >= 4.0.0-RC1, <= 4.17.7 and >= 5.0.0-RC1, <= 5.9.13, and is fixed in 4.17.8 and 5.9.14.
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
Affected packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
craftcms/cmsPackagist | >= 4.0.0-RC1, < 4.17.8 | 4.17.8 |
craftcms/cmsPackagist | >= 5.0.0-RC1, < 5.9.14 | 5.9.14 |
Affected products
2- Range: >= 5.0.0-RC1, <= 5.9.13
Patches
Vulnerability mechanics
References
5- github.com/advisories/GHSA-x76w-8c62-48mgghsaADVISORY
- nvd.nist.gov/vuln/detail/CVE-2026-56384ghsaADVISORY
- github.com/craftcms/cms/commit/d30df3112220db1ffd6726a3ed11857014c7fb27nvdWEB
- github.com/craftcms/cms/security/advisories/GHSA-x76w-8c62-48mgnvdWEB
- www.vulncheck.com/advisories/craft-cms-missing-authorization-in-assets-preview-thumb-endpointnvdWEB
News mentions
1- Craft CMS: Nine Vulnerabilities Including RCE and SSRF Disclosed in BatchVypr Intelligence · Jun 21, 2026