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

CVE-2026-8351

MEDIUM · 6.4 CVSS v3.1 Published 2026-07-03
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
70/100
Remediation priority · Elevated
Remotely reachable Zero-click 7 weeks old

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
The RTMKit plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the Advanced Heading widget's 'Background Text' parameter in versions up to, and including, 2.0.7 This is due to insufficient output escaping on the 'background_text_heading' setting in the render() function, which concatenates the value directly into an HTML attribute without applying esc_attr(). This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

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 · high confidence

The RTMKit WordPress plugin versions up to 2.0.7 contain a stored XSS vulnerability in the Advanced Heading widget. The 'background_text_heading' parameter is rendered directly into an HTML attribute within the render() function without applying esc_attr() escaping, allowing authenticated attackers with contributor-level access or higher to inject malicious JavaScript that executes when users view affected pages.

MitigationApply esc_attr() to the background_text_heading value in the render() function before outputting it into the HTML attribute, or update to a patched version if available.

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
None
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/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. Verify RTMKit plugin installation and version
    In WordPress admin, go to Plugins > Installed Plugins and locate RTMKit. Note the version number displayed. Alternatively, check the plugin header in /wp-content/plugins/rtmkit/includes/advanced-heading-widget.php or the main plugin file.
    Affected if RTMKit plugin is installed and version is 2.0.7 or lower
  2. Identify use of Advanced Heading widget
    Review pages, posts, or widget areas where the Advanced Heading widget from RTMKit has been added. Check the WP database in posts table for meta_key containing 'rtmkit_advanced_heading' or widget settings in wp_options.
    Affected if Advanced Heading widget is actively used on any published content
  3. Inspect background_text_heading parameter
    Locate the render() function in the Advanced Heading widget file (typically in /wp-content/plugins/rtmkit/includes/widgets/advanced-heading-widget.php). Search for the background_text_heading output and verify whether esc_attr() is applied before rendering into the HTML attribute.
    Affected if The background_text_heading value is rendered into HTML without esc_attr() escaping (vulnerable code pattern: echo "<... $background_text_heading ...>")
  4. Confirm injected script execution
    View a page containing the Advanced Heading widget with a non-admin user account (contributor or above). Inspect the page source around the heading element and check if the background_text_heading value appears unescaped in an HTML attribute.
    Affected if The background_text_heading value appears as raw text in an HTML attribute without HTML entity encoding (e.g., quotes or script tags are not converted to &quot; or &lt;)

User is affected if RTMKit plugin version is 2.0.7 or lower, the Advanced Heading widget is in use, and the background_text_heading parameter renders without esc_attr() escaping in the HTML 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

Apply esc_attr() to the background_text_heading value in the render() function before outputting it into the HTML attribute, or update to a patched version if available.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,240
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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-2026-8351 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

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