CVE-2026-56384

MEDIUM

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

Title source: cna
STIX 2.1

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.

References (3)

Core 3
Core References
Vendor Advisory vendor-advisory
GHSA Advisory GHSA-x76w-8c62-48mg
https://github.com/craftcms/cms/security/advisories/GHSA-x76w-8c62-48mg
Third Party Advisory third-party-advisory
VulnCheck Advisory: Craft CMS - Missing Authorization in assets/preview-thumb Endpoint
https://www.vulncheck.com/advisories/craft-cms-missing-authorization-in-assets-preview-thumb-endpoint

Scores

CVSS v3 4.3
EPSS 0.0019
EPSS Percentile 9.2%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-862
Status published
Products (4)
craftcms/cms 4.0.0-RC1 - 4.17.8
craftcms/cms 4.17.8
craftcms/cms 5.0.0-RC1 - 5.9.14
craftcms/cms 5.9.14
Published Jun 21, 2026
Tracked Since Jun 21, 2026