Craft CMS up to 5.9.20 Edit Permission actionSaveEntry improper authorization

Summaryinfo

A vulnerability, which was classified as critical, has been found in Craft CMS up to 5.9.20. This vulnerability affects the function theEntriesController::actionSaveEntry of the component Edit Permission Handler. The manipulation leads to improper authorization. This vulnerability is traded as CVE-2026-50279. It is possible to initiate the attack remotely. There is no exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Craft CMS up to 5.9.20 and classified as critical. This issue affects the function theEntriesController::actionSaveEntry of the component Edit Permission Handler. The manipulation with an unknown input leads to a improper authorization vulnerability. Using CWE to declare the problem leads to CWE-285. The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

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.

It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2026-50279 since 06/04/2026. The exploitation is known to be easy. The attack may be initiated remotely. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1548.002 according to MITRE ATT&CK.

Upgrading to version 5.9.21 eliminates this vulnerability. Applying the patch 9cc493be8b414d7116c7f2bc2a6d0926e73f1248 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

• Content Management System

Vendor

• Craft

Name

• CMS

Version

• 5.9.0
• 5.9.1
• 5.9.2
• 5.9.3
• 5.9.4
• 5.9.5
• 5.9.6
• 5.9.7
• 5.9.8
• 5.9.9
• 5.9.10
• 5.9.11
• 5.9.12
• 5.9.13
• 5.9.14
• 5.9.15
• 5.9.16
• 5.9.17
• 5.9.18
• 5.9.19
• 5.9.20

License

• free

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Be aware that VulDB is the high quality source for vulnerability data.

Discussion