GHSA-f4h3-qhg5-j6mq: Duplicate Advisory Craft CMS: Authorized Asset "preview Vulnerability

MODERATE
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CVSS 4.3
CWE-639
Published
Advisory Summary

GHSA-f4h3-qhg5-j6mq is a MODERATE (CVSS 4.3) craft cms: authorized asset "preview vulnerability (CWE-639: Authorization Bypass Through User-Controlled Key) affecting Duplicate Advisory libraries in the Packagist ecosystem. The issue involves craft cms: authorized asset "preview file" requests bypass allows users without asset access to retrieve private preview metadata. Remediation is available in the latest vendor maintenance releases.

GHSA-f4h3-qhg5-j6mq at a Glance

CVE Identifier N/A
GHSA Identifier GHSA-f4h3-qhg5-j6mq
Severity MODERATE
CVSS v3.1 Base Score 4.3
CWE Classification CWE-639: Authorization Bypass Through User-Controlled Key
Affected Product Duplicate Advisory
Package Ecosystem Packagist
Published Date
Last Updated

Security Impact

CVSS: 4.3

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality Low (C:L)
Integrity None (I:N)
Availability None (A:N)

How to Fix GHSA-f4h3-qhg5-j6mq

To remediate this vulnerability, upgrade all affected Duplicate Advisory dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

craftcms/cms fixed: Latest secure release 
Upgrade craftcms/cms to Latest secure release
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for craftcms/cms

How to Check if You Are Affected

To determine whether your application is affected by GHSA-f4h3-qhg5-j6mq, inspect your project dependencies for Duplicate Advisory:

inspect dependencies for craftcms/cms

Analyze the terminal output to locate any version of Duplicate Advisory in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-639: Authorization Bypass Through User-Controlled Key, where the system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data. In Duplicate Advisory, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

## Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-44px-qjjc-xrhq. This link is maintained to preserve external references. ## Original Description Craft CMS versions >= 5.0.0-RC1, <= 5.9.13 and >= 4.0.0-RC1, <= 4.17.7 contain an authorization bypass in the assets/preview-file endpoint. The action does not enforce per-asset view authorization before returning preview content, allowing an authenticated low-privileged user to supply a controlled assetId for an asset they are not permitted to view and still receive preview response data (previewHtml), including a private preview image route containing the target private assetId. Fixed in 5.9.14 and 4.17.8.

GHSA-f4h3-qhg5-j6mq Affected Duplicate Advisory Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
craftcms/cms
 Packagist
≥ 5.0.0-RC1
≤ 5.9.13

References

GitHub Advisory / Wiki ADVISORY
https://github.com/craftcms/cms/security/advisories/GHSA-44px-qjjc-xrhq
NVD — GHSA-f4h3-qhg5-j6mq NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-56385
Security Fix Commit FIX COMMIT
https://github.com/craftcms/cms/commit/d30df3112220db1ffd6726a3ed11857014c7fb27
www.vulncheck.com/advisories/craft-cm... WEB
https://www.vulncheck.com/advisories/craft-cms-authorization-bypass-in-assets-preview-file-endpoint

Frequently Asked Questions

What is GHSA-f4h3-qhg5-j6mq?
GHSA-f4h3-qhg5-j6mq is a security vulnerability in Duplicate Advisory involving Craft CMS: Authorized asset "preview file" requests bypass allows users without asset access to retrieve private preview metadata under CWE-639: Authorization Bypass Through User-Controlled Key.
Which Duplicate Advisory versions are affected?
Affected versions include releases prior to current release patches across affected packages: craftcms/cms.
What version fixes GHSA-f4h3-qhg5-j6mq?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is craftcms/cms affected?
Yes, craftcms/cms is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What is the CVSS score of GHSA-f4h3-qhg5-j6mq?
GHSA-f4h3-qhg5-j6mq has a CVSS v3.1 base score of 4.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.
What CWE is associated with GHSA-f4h3-qhg5-j6mq?
GHSA-f4h3-qhg5-j6mq is classified under CWE-639: Authorization Bypass Through User-Controlled Key (The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.).
How can I check Packagist dependencies for GHSA-f4h3-qhg5-j6mq?
Run the dependency tree command: 'inspect dependencies for craftcms/cms'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-f4h3-qhg5-j6mq",
  "modified" : "2026-08-06T21:56:22Z",
  "published" : "2026-06-21T15:31:24Z",
  "withdrawn" : "2026-08-06T21:56:22Z",
  "aliases" : [ ],
  "summary" : "Duplicate Advisory: Craft CMS: Authorized asset \"preview file\" requests bypass allows users without asset access to retrieve private preview metadata",
  "details" : "## Duplicate Advisory\n\nThis advisory has been withdrawn because it is a duplicate of GHSA-44px-qjjc-xrhq. This link is maintained to preserve external references.\n\n## Original Description\nCraft CMS versions >= 5.0.0-RC1, <= 5.9.13 and >= 4.0.0-RC1, <= 4.17.7 contain an authorization bypass in the assets/preview-file endpoint. The action does not enforce per-asset view authorization before returning preview content, allowing an authenticated low-privileged user to supply a controlled assetId for an asset they are not permitted to view and still receive preview response data (previewHtml), including a private preview image route containing the target private assetId. Fixed in 5.9.14 and 4.17.8.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "craftcms/cms"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "5.0.0-RC1"
      }, {
        "last_affected" : "5.9.13"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/craftcms/cms/security/advisories/GHSA-44px-qjjc-xrhq"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-56385"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/craftcms/cms/commit/d30df3112220db1ffd6726a3ed11857014c7fb27"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/craft-cms-authorization-bypass-in-assets-preview-file-endpoint"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-639" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-08-06T21:56:22Z",
    "nvd_published_at" : "2026-06-21T14:16:26Z"
  }
}