CVE-2026-41128: CWE-862: Missing Authorization in craftcms cms
Craft CMS versions 5. 6. 0 through 5. 9. 14 contain a missing authorization vulnerability in the actionSavePermissions() endpoint. A user with only viewUsers permission can remove arbitrary users from all user groups because the system does not enforce authorization checks for group removals. This issue is patched in version 5. 9. 15.
AI Analysis
Technical Summary
The vulnerability in Craft CMS (CVE-2026-41128) arises from a missing authorization check in the actionSavePermissions() endpoint. While the system enforces authorization when adding users to groups, it fails to do so when removing users from groups. Specifically, submitting an empty groups value removes all existing group memberships for a user, even if the requester only has viewUsers permission. This allows unauthorized modification of user group memberships. The issue affects versions 5.6.0 up to but not including 5.9.15, where a patch has been applied.
Potential Impact
An attacker with viewUsers permission can remove users from all user groups without proper authorization. This could lead to privilege disruption or denial of access for affected users. The CVSS 4.0 base score is 5.3 (medium severity), reflecting the limited privileges required and the impact on user group memberships.
Mitigation Recommendations
A patch is available in Craft CMS version 5.9.15 that addresses this missing authorization vulnerability. Users should upgrade to version 5.9.15 or later to remediate this issue. Since no vendor advisory was provided, patch status is inferred from the description stating version 5.9.15 contains the fix.
CVE-2026-41128: CWE-862: Missing Authorization in craftcms cms
Description
Craft CMS versions 5. 6. 0 through 5. 9. 14 contain a missing authorization vulnerability in the actionSavePermissions() endpoint. A user with only viewUsers permission can remove arbitrary users from all user groups because the system does not enforce authorization checks for group removals. This issue is patched in version 5. 9. 15.
CVSS v4.0
Score 5.3medium
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in Craft CMS (CVE-2026-41128) arises from a missing authorization check in the actionSavePermissions() endpoint. While the system enforces authorization when adding users to groups, it fails to do so when removing users from groups. Specifically, submitting an empty groups value removes all existing group memberships for a user, even if the requester only has viewUsers permission. This allows unauthorized modification of user group memberships. The issue affects versions 5.6.0 up to but not including 5.9.15, where a patch has been applied.
Potential Impact
An attacker with viewUsers permission can remove users from all user groups without proper authorization. This could lead to privilege disruption or denial of access for affected users. The CVSS 4.0 base score is 5.3 (medium severity), reflecting the limited privileges required and the impact on user group memberships.
Mitigation Recommendations
A patch is available in Craft CMS version 5.9.15 that addresses this missing authorization vulnerability. Users should upgrade to version 5.9.15 or later to remediate this issue. Since no vendor advisory was provided, patch status is inferred from the description stating version 5.9.15 contains the fix.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-04-17T12:59:15.737Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 69e80c4119fe3cd2cd06bb15
Added to database: 4/21/2026, 11:46:09 PM
Last enriched: 4/29/2026, 11:12:51 AM
Last updated: 6/5/2026, 8:13:52 PM
Views: 75
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