Permission Vulnerability in Craft CMS 5.6.0 to 5.9.14
CVE-2026-41128

5.3MEDIUM

Key Information:

Vendor

Craftcms

Status
Cms
Vendor
CVE Published:
21 April 2026

What is CVE-2026-41128?

Craft CMS, specifically versions 5.6.0 through 5.9.14, contains a vulnerability within the actionSavePermissions() endpoint enabling users with merely viewUsers permission to delete any user from all user groups. This occurs due to inadequate authorization checks when removing users, as the _saveUserGroups() function fails to validate the user’s permissions for group removals while still enforcing them for additions. As a result, if an empty groups value is submitted, it inadvertently results in the deletion of all existing group memberships for the affected users. The security flaw has been addressed in Craft CMS version 5.9.15.

Affected Version(s)

cms >= 5.6.0, < 5.9.15

References

https://github.com/craftcms/cms/security/advisories/GHSA-...
x_refsource_CONFIRM
https://github.com/craftcms/cms/commit/b135384808ad43fcf8...
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CVSS V4

Score:
5.3
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.