CVE-2026-50279: CWE-285: Improper Authorization in craftcms cms
Craft CMS is a content management system (CMS). IN versions 5.0.0-RC1 and above prior to 5.9.21, theEntriesController::actionSaveEntry() performs entry-edit permission checks before request-controlled author changes are applied to the model, allowing for authorship spoofing. The subsequent author mutation path accepts attacker-supplied authors / author parameters and allows the change when the current user is one of the old authors. Because the controller does not re-run authorization after mutating the author list, a low-privileged user can reassign an entry’s authorship to another user without holding the dedicated peer-author-change permission. This issue has been fixed in version 5.9.21.
AI Analysis
Technical Summary
In Craft CMS versions 5.0.0-RC1 through 5.9.20, the EntriesController::actionSaveEntry() method performs entry-edit permission checks before applying changes to the entry's authorship. Because the controller accepts attacker-supplied author parameters and does not re-run authorization after modifying the author list, a user who is already an author can spoof authorship by reassigning the entry to another user without holding the dedicated peer-author-change permission. This improper authorization vulnerability (CWE-285) allows unauthorized authorship reassignment. The issue is resolved in version 5.9.21.
Potential Impact
An attacker with low privileges who is already an author of an entry can reassign the entry's authorship to another user without proper authorization. This could lead to unauthorized changes in content ownership and potentially bypass intended access controls related to content authorship. There is no indication of remote code execution or data disclosure beyond authorship manipulation.
Mitigation Recommendations
A fix is available in Craft CMS version 5.9.21. Users should upgrade to version 5.9.21 or later to remediate this vulnerability. Since this is not a cloud service, manual patching is required. Patch status is confirmed by the vendor advisory stating the issue is fixed in 5.9.21.
CVE-2026-50279: CWE-285: Improper Authorization in craftcms cms
Description
Craft CMS is a content management system (CMS). IN versions 5.0.0-RC1 and above prior to 5.9.21, theEntriesController::actionSaveEntry() performs entry-edit permission checks before request-controlled author changes are applied to the model, allowing for authorship spoofing. The subsequent author mutation path accepts attacker-supplied authors / author parameters and allows the change when the current user is one of the old authors. Because the controller does not re-run authorization after mutating the author list, a low-privileged user can reassign an entry’s authorship to another user without holding the dedicated peer-author-change permission. This issue has been fixed in version 5.9.21.
CVSS v4.0
Score 7.6high
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
In Craft CMS versions 5.0.0-RC1 through 5.9.20, the EntriesController::actionSaveEntry() method performs entry-edit permission checks before applying changes to the entry's authorship. Because the controller accepts attacker-supplied author parameters and does not re-run authorization after modifying the author list, a user who is already an author can spoof authorship by reassigning the entry to another user without holding the dedicated peer-author-change permission. This improper authorization vulnerability (CWE-285) allows unauthorized authorship reassignment. The issue is resolved in version 5.9.21.
Potential Impact
An attacker with low privileges who is already an author of an entry can reassign the entry's authorship to another user without proper authorization. This could lead to unauthorized changes in content ownership and potentially bypass intended access controls related to content authorship. There is no indication of remote code execution or data disclosure beyond authorship manipulation.
Mitigation Recommendations
A fix is available in Craft CMS version 5.9.21. Users should upgrade to version 5.9.21 or later to remediate this vulnerability. Since this is not a cloud service, manual patching is required. Patch status is confirmed by the vendor advisory stating the issue is fixed in 5.9.21.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-06-04T16:26:05.985Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a45a80827e9c797195b4138
Added to database: 07/01/2026, 23:51:36 UTC
Last enriched: 07/09/2026, 09:22:44 UTC
Last updated: 08/15/2026, 12:41:09 UTC
Views: 87
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