Craft CMS up to 4.17.15/5.9.22 CraftSupport Widget cross site scripting

Summaryinfo

A vulnerability was found in Craft CMS up to 4.17.15/5.9.22. It has been declared as critical. This affects an unknown function of the component CraftSupport Widget. Executing a manipulation can lead to cross site scripting. The identification of this vulnerability is CVE-2026-55790. The attack may be launched remotely. There is no exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical was found in Craft CMS up to 4.17.15/5.9.22. This vulnerability affects some unknown processing of the component CraftSupport Widget. The manipulation with an unknown input leads to a cross site scripting vulnerability. The CWE definition for the vulnerability is CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. As an impact it is known to affect integrity. CVE summarizes:

Craft CMS is a content management system (CMS). In versions 5.0.0-RC1 through 5.9.22 and 4.0.0-RC1 through 4.17.15, an attacker with only a GitHub account can plant a JavaScript payload in a craftcms/cms issue title. When a Craft admin uses the CraftSupport widget’s "Give feedback" screen and types a search term that returns the poisoned issue, the payload executes in the admin’s control panel session. No control panel account or elevated privileges are required on the attacker’s side. This issue has been fixed in versions 4.17.16 and 5.9.23.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-55790 since 06/17/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1059.007.

Upgrading to version 4.17.16 or 5.9.23 eliminates this vulnerability. Applying the patch 6bbb66038a268552180ca5c8eed9f46ea25a4417 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.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Content Management System

Vendor

• Craft

Name

• CMS

Version

• 4.17.0
• 4.17.1
• 4.17.2
• 4.17.3
• 4.17.4
• 4.17.5
• 4.17.6
• 4.17.7
• 4.17.8
• 4.17.9
• 4.17.10
• 4.17.11
• 4.17.12
• 4.17.13
• 4.17.14
• 4.17.15
• 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
• 5.9.21
• 5.9.22

License

• free

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Once again VulDB remains the best source for vulnerability data.

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