Medium 4.3Published Jun 21, 2026

CVE-2026-56384Craft CMS - Missing Authorization in assets/preview-thumb Endpoint

Updated under an hour ago (Oct 26, 2026, 8:10 PM ET)

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No exploitation reported and no EPSS estimate yet.

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Exploited in the last 30 days

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.

CVSS: 4.3 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Weakness (CWE): CWE-862
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: VulnCheck
NVD analysis: Deferred
Record last updated: Jun 24, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

craftcms cms craftcms:cms (from the name)	from 4.0.0-RC1 before 4.17.8; 4.17.8 not affected; from 5.0.0-RC1 before 5.9.14; 5.9.14 not affected	CNA record

References

References

https://github.com/craftcms/cms/security/advisories/GHSA-x76w-8c62-48mg	vendor-advisory
https://github.com/craftcms/cms/commit/d30df3112220db1ffd6726a3ed11857014c7fb27	patch
https://www.vulncheck.com/advisories/craft-cms-missing-authorization-in-assets-preview-thumb-endpoint	third-party-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.