CVE-2026-55794: Craft CMS: Potential authenticated Remote Code Execution via referrer redirect
Requirements:
Control panel access Permissions to edit an entry
Details
Control panel users with the ability to edit entries can execute unsandboxed Twig code via the HTTP Referrer header.
The issue happens when a user is saving entries. Strings for a signed redirect URL are being compiled as a Twig template via renderObjectTemplate(), and while a sandboxed alternative already exists (renderSandboxedObjectTemplate()), it is not used in this case. This signed URL can be specified by users, as it is reflected in the “Referer” HTTP request header, which is under attacker control.
This has been fixed in Craft 5.10.0. Affected users should update to that version or higher to get the fix.
Resources
https://github.com/craftcms/cms/pull/18680
Other sources
Craft CMS is a content management system (CMS). In versions 5.9.0 and above prior to 5.10.0, control panel users with the ability to edit entries can execute unsandboxed Twig code via the HTTP Referrer header, potentially leading to authenticated RCE. The issue happens when a user is saving entries. Strings for a signed redirect URL are being compiled as a Twig template via renderObjectTemplate(), and while a sandboxed alternative already exists (renderSandboxedObjectTemplate()), it is not used in this case. This signed URL can be specified by users, as it is reflected in the “Referer” HTTP request header, which is under attacker control. This issue has been fixed in version 5.10.0.
— NVD
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
composer/craftcms/cmsto a version that resolves this vulnerability.Fixed in 5.10.0 - Upgrade
Upgrade
Craft CMSto a version that resolves this vulnerability.Fixed in 5.10.0 - Compensating control
Restrict access to the Craft CMS control panel so that only trusted users can edit entries, since authenticated control panel users with entry-editing permission can trigger the issue via the attacker-controlled HTTP Referer header while saving entries.
Event History
Frequently Asked Questions
What is the severity of CVE-2026-55794?
The severity of CVE-2026-55794 is high with a CVSS score of 8.7.
What is CVE-2026-55794?
CVE-2026-55794 is a vulnerability in Craft CMS that allows authenticated users to execute unsandboxed Twig code via the HTTP Referrer header.
How do I fix CVE-2026-55794?
To fix CVE-2026-55794, upgrade your Craft CMS to version 5.10.0 or later.
Which versions of Craft CMS are affected by CVE-2026-55794?
Craft CMS versions 5.9.0 to 5.9.x, prior to 5.10.0, are affected by CVE-2026-55794.
What type of attack does CVE-2026-55794 represent?
CVE-2026-55794 represents a risk of authenticated Remote Code Execution through code injection.