Unrated severityNVD Advisory· Published Jun 21, 2026

Craft CMS - Missing Authorization in assets/preview-thumb Endpoint

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 products

Packagist/CMSinferred
Range: >= 5.0.0-RC1, <= 5.9.13
Package: https://packagist.org/packages/craftcms/cms
Craftcms/Craft CMSllm-fuzzy
Range: >=4.0.0-RC1, <=4.17.7; >=5.0.0-RC1, <=5.9.13

Patches

Vulnerability mechanics

AI mechanics synthesis has not run for this CVE yet.

References

github.com/craftcms/cms/commit/d30df3112220db1ffd6726a3ed11857014c7fb27mitrepatch
github.com/craftcms/cms/security/advisories/GHSA-x76w-8c62-48mgmitrevendor-advisory
www.vulncheck.com/advisories/craft-cms-missing-authorization-in-assets-preview-thumb-endpointmitrethird-party-advisory

News mentions

No linked articles in our index yet.

cvss	0.000
epss	0.000
exploit	0.000
kev	0.000
patch	-0.070
ransomware	0.000