CVE-2026-56384

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.

Database specific

{
    "cna_assigner":  "VulnCheck",
    "cwe_ids":  [
        "CWE-862"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/56xxx/CVE-2026-56384.json"
}

References

Affected packages

Git / github.com/craftcms/cms

Affected ranges

Type

GIT

Repo

https://github.com/craftcms/cms

Events

Introduced

daac7c1da2f701f2e9ddee1da1457ce61660b581

Fixed

3262cfa628ade304f0e565f9e45b52fab0f32df3

Introduced

04755d93f86d07cc183db47db8a0eee106892e30

Fixed

13c50dd550fabe74fe5317aeca090d286f1c7556

Fixed

d30df3112220db1ffd6726a3ed11857014c7fb27

Database specific

Show details

{
    "extracted_events":  [
        {
            "range":  [
                {
                    "introduced":  "4.0.0-RC1"
                },
                {
                    "fixed":  "4.17.8"
                }
            ],
            "source":  "AFFECTED_FIELD",
            "strategy":  "StandardRange"
        },
        {
            "range":  [
                {
                    "introduced":  "5.0.0-RC1"
                },
                {
                    "fixed":  "5.9.14"
                }
            ],
            "source":  "AFFECTED_FIELD",
            "strategy":  "StandardRange"
        },
        {
            "range":  [
                {
                    "fixed":  "d30df3112220db1ffd6726a3ed11857014c7fb27"
                }
            ],
            "source":  "REFERENCES_COMMIT"
        }
    ]
}

Database specific

source

"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-56384.json"