CVE-2026-56381 Craft CMS - Stored XSS via User Group Name in User Permissions Page
Admins can inject JavaScript via user group names in Craft CMS, leading to stored XSS and potential account takeover when viewed by others.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-56381?
CVE-2026-56381 is a medium-severity cross-site scripting vulnerability in craftcms cms, published on 21 Jun 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Official description
Craft CMS from version 5.0.0-RC1 contains a stored cross-site scripting vulnerability in the User Permissions page where user group names are rendered without proper HTML escaping. Attackers with admin access can inject arbitrary JavaScript via the user group name field that executes when other users view or edit permissions.
Weakness: CWE-79
Which versions are affected by CVE-2026-56381?
2 open source packages ship an affected version, including craftcms/cms.
| Package | Affected | Fixed in |
|---|---|---|
craftcms/cms Packagist | From 5.0.0-RC1 | 5.8.22 |
craftcms/cms Packagist | From 5.0.0-RC1 | 5.8.22 |
How do I fix CVE-2026-56381?
Upgrade craftcms/cms to 5.8.22 or later.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-56381 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-56381 exists.
Sources
Also known as GHSA-g3hp-vvqf-8vw6.