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

CVE-2026-9811

MEDIUM · 5.4 CVSS v3.1 Published 2026-05-29
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
58/100
Remediation priority · Elevated
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
A stored Cross-Site Scripting (XSS) vulnerability exists in the project selector component of Mautic 7. When rendering selection menus for associating projects with system entities, the application fails to sanitize project names returned via AJAX before injecting them into the DOM as option fields. An authenticated user with permissions to create projects can exploit this to store a malicious script payload in the project's name. When another administrative user subsequently opens an entity editor containing the project selector, the injected script executes within the context of their active browser session. This could allow an attacker to hijack the session, perform unauthorized state coordination, or access organizational data within the dashboard.

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

Mautic 7 fails to sanitize project names returned via AJAX before rendering them as option fields in the project selector component. An authenticated user with project creation permissions can store a malicious script payload in a project's name. When administrative users open entity editors containing the project selector, the unsanitized project name is injected into the DOM, causing the stored XSS payload to execute in their browser session.

MitigationImplement output encoding/sanitization on project names received via AJAX before they're inserted into the DOM as option fields. Additionally, add server-side input validation for project names to prevent injection of scriptable content.

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
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/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 Mautic installation and version
    Check your Mautic installation's version number by accessing the admin dashboard's 'System Info' or 'Configuration' section, or by inspecting the app/config/local.php file or composer.json for the installed version.
    Affected if The installed version is Mautic 7.x (any subversion).
  2. Verify project selector component is in use
    Determine if your Mautic instance uses the project selector feature by navigating to the Campaigns, Emails, or Forms editors and checking if a project dropdown/selector field appears in any entity creation or edit forms.
    Affected if The project selector dropdown is rendered in any admin interface area.
  3. Inspect AJAX response for project names
    Use browser developer tools (Network tab) to trigger the project selector dropdown load, locate the AJAX request fetching project names, and examine the raw response payload before DOM insertion.
    Affected if The AJAX response contains raw project name data without visible encoding or sanitization markers (such as HTML entities).
  4. Check browser console for XSS execution
    Create a test project with a name containing a benign XSS payload (such as <img src=x onerror=alert(1)>), then view the project selector as a different administrative user and observe if the JavaScript executes in the browser console.
    Affected if The script payload executes and triggers an alert or error in the browser console when the dropdown loads.

You are affected if running Mautic 7 with the project selector component enabled and the AJAX response for project names does not contain sanitized/encoded output.

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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Implement output encoding/sanitization on project names received via AJAX before they're inserted into the DOM as option fields. Additionally, add server-side input validation for project names to prevent injection of scriptable content.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,780
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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-2026-9811 in production — separate from our analysis above.

No notes yet

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What this is

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What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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