CVE-2026-42558 Xibo Vulnerable to Stored XSS and Iframe Sandbox Escape via Data Connector Script in DataSet
Authorized users with specific DataSet privileges can exploit stored XSS and iframe sandbox escape to execute arbitrary code or bypass security controls.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-42558?
CVE-2026-42558 is a high-severity cross-site scripting vulnerability in xibosignage xibo-cms, published on 10 Jun 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
Xibo is an open source digital signage platform with a web content management system and Windows display player software. Prior to 4.4.2, a vulnerability chain consisting of Stored XSS and Iframe Sandbox escape in the Xibo CMS allows users with DataSet permissions to use the Data Connector functionality to craft messages which escape the sandbox and facilitate XSS. Exploitation of the vulnerability is possible on behalf of an authorized user who has both of the following privileges, which are not granted to non-admins as standard: Include "Add DataSet" button to allow for additional DataSets to be created independently to Layouts Users should upgrade to version 4.4.2 which fixes this issue. Upgrading to a fixed version is necessary to remediate. Users unable to upgrade should revoke such privileges from users they do not trust.
Which versions are affected by CVE-2026-42558?
How do I fix CVE-2026-42558?
No fix has been published for CVE-2026-42558 yet. Limit exposure of the affected software until one is available.
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-2026-42558 being exploited?
There is no known exploitation of CVE-2026-42558 in the wild and no public exploit code.
Sources
Also known as GHSA-6389-j56c-9fww.