CVE-2026-56393: Craft CMS - Multiple Stored Cross-Site Scripting in Settings Names and Field Options
Craft CMS 4.x (>= 4.0.0-RC1, < 4.17.0-beta.1) and 5.x (>= 5.0.0-RC1, < 5.9.0-beta.1) contain multiple stored cross-site scripting vulnerabilities where settings names and field option labels are rendered without sanitization (e.g., via the checkbox.twig template, which used {{ label|raw }}). An authenticated administrator (with allowAdminChanges enabled) can inject malicious payloads into section names, volume names, user group names, global set names, generated field names, checkbox/radio option labels, and custom source labels, causing arbitrary JavaScript to execute in other users' control-panel sessions. Fixed in 4.17.0-beta.1 and 5.9.0-beta.1.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Craft CMSto a version that resolves this vulnerability.Fixed in 4.17.0-beta.1 - Upgrade
Upgrade
Craft CMSto a version that resolves this vulnerability.Fixed in 5.9.0-beta.1 - Configuration
Set allowAdminChanges to false (disable allowAdminChanges) to prevent authenticated administrators from making settings/field option changes that could be used to inject stored XSS payloads.
Craft CMS allowAdminChanges = false
Event History
Frequently Asked Questions
What is the severity of CVE-2026-56393?
The severity of CVE-2026-56393 is classified as medium with a score of 4.8.
How do I fix CVE-2026-56393?
To fix CVE-2026-56393, upgrade Craft CMS to version 4.17.0-beta.1 or later for 4.x, and 5.9.0-beta.1 or later for 5.x.
What type of vulnerability is CVE-2026-56393?
CVE-2026-56393 is classified as a stored cross-site scripting (XSS) vulnerability affecting Craft CMS.
What systems are affected by CVE-2026-56393?
CVE-2026-56393 affects Craft CMS versions 4.x prior to 4.17.0-beta.1 and 5.x prior to 5.9.0-beta.1.
What are the potential impacts of CVE-2026-56393?
The potential impacts of CVE-2026-56393 include unauthorized script execution and possible data theft or session hijacking.