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Cross-site Scripting (XSS)Weakness · CWE-79

CVE-2026-42558

HIGH · 7.6 CVSS v3.1 Published 2026-06-10
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
80/100
Remediation priority · High
Remotely reachable

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

A vulnerability chain combining Stored XSS and iframe sandbox escape in Xibo CMS allows users with DataSet permissions to craft malicious messages via the Data Connector functionality that escape the sandbox and achieve XSS. Exploitation requires the 'Add DataSet' privilege which is not granted to non-admins by default.

MitigationUpgrade Xibo CMS to version 4.4.2 or higher. If upgrading is not possible, revoke the 'Add DataSet' privilege from untrusted users.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
Required
Scope
Changed
Confidentiality
High
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify Xibo CMS installation and version
    Locate the Xibo installation directory and check the version file or admin panel for the current Xibo CMS version number
    Affected if The installed version is prior to 4.4.2 (versions 4.0.0 through 4.4.1 are affected)
  2. Confirm DataSet module is enabled
    Access the Xibo admin panel and verify the DataSet/Data Connector module is available and not disabled in the system settings
    Affected if The DataSet module is enabled and accessible to users
  3. Check user permissions for DataSet functionality
    Navigate to User management in the admin panel and review which users or user groups have DataSet permissions assigned
    Affected if Any user account has DataSet permissions configured
  4. Identify users with Add DataSet button privilege
    Review the role or permission configuration to determine which users have the 'Add DataSet' or equivalent privilege that allows creating new data sets
    Affected if One or more user accounts have the Add DataSet button privilege, especially untrusted or low-privilege users
  5. Inspect Data Connector configurations for suspicious content
    If DataSet permissions exist, review any existing Data Connector entries for unusual script tags, iframe elements, or sandbox-escaped content in message fields
    Affected if Malicious payloads have been injected into Data Connector message fields

A user is affected if running Xibo CMS version 4.4.1 or earlier, has the DataSet module enabled, and has user accounts with both DataSet permissions and Add DataSet button privileges present in the environment.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade Xibo CMS to version 4.4.2 or higher. If upgrading is not possible, revoke the 'Add DataSet' privilege from untrusted users.

Recommended fix High confidence

4.4.2

  1. 1. Backup your Xibo CMS database and files before upgrading.
  2. 2. Verify current Xibo CMS version by checking the admin panel or running `php version` in the CLI.
  3. 3. Download Xibo CMS version 4.4.2 from the official GitHub releases (github.com/xibosignage/xibo-cms/releases).
  4. 4. Extract the upgrade package to your web server document root, preserving custom configurations.
  5. 5. Run database migrations if required: `php artisan migrate` from the CMS root directory.
  6. 6. Clear caches: `php artisan cache:clear` and `php artisan view:clear`.
  7. 7. Verify the upgrade was successful by checking the version in the admin panel.
  8. 8. Confirm the "Add DataSet" privilege is only granted to trusted users if immediate upgrade is not possible.

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing4.0 h
  • Review / QA2.0 h
15.0 hours of engineering $2,640
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-42558 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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