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

CVE-2026-9643

HIGH · 7.2 CVSS v3.1 Published 2026-06-24
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
81/100
Remediation priority · High
Remotely reachable No privileges Zero-click

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 WP Meta SEO plugin for WordPress is vulnerable to Unauthenticated Stored Cross-Site Scripting via the REQUEST_URI server variable in all versions up to, and including, 4.5.18. When the plugin's `wpmsTemplateRedirect()` hook detects a 404, it concatenates `$_SERVER['HTTP_HOST']` with the raw `$_SERVER['REQUEST_URI']` and inserts that value verbatim into the `wp_wpms_links.link_url` column via `$wpdb->insert()`. This makes it possible for unauthenticated attackers to inject arbitrary web scripts that execute whenever an administrator views the plugin's 404 & Redirects admin page (`/wp-admin/admin.php?page=metaseo_broken_link`).

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 WP Meta SEO plugin directly uses unsanitized `$_SERVER['REQUEST_URI']` and `$_SERVER['HTTP_HOST']` values in database inserts when handling 404 errors via the `wpmsTemplateRedirect()` hook. This allows unauthenticated attackers to inject persistent JavaScript that executes when administrators access the plugin's 404 & Redirects admin page.

MitigationUpdate to a patched version of WP Meta SEO. Until then, disable the plugin or implement web application firewall rules to block malicious requests with XSS payloads in the URI.

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
None
User interaction
None
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/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. Identify WP Meta SEO plugin installation
    In WordPress admin, go to Plugins > Installed Plugins and locate 'WP Meta SEO', or check the /wp-content/plugins/ directory for the wp-meta-seo folder. Note the version number displayed.
    Affected if The plugin is installed and the version is lower than the patched release.
  2. Determine if 404 handling is active
    Navigate to WP Meta SEO > 404 & Redirects in the admin dashboard. Check whether the plugin's 404 error logging or redirect functionality is enabled.
    Affected if The 404 & Redirects feature is turned on, allowing the vulnerable code path in wpmsTemplateRedirect() to execute.
  3. Inspect database for suspicious 404 records
    Access the WordPress database (via phpMyAdmin or command line) and query tables related to meta SEO 404 tracking, looking for URI or host values containing script tags, javascript:, or other XSS patterns.
    Affected if Database entries contain unsanitized URI/host data with embedded script tags or event handlers.
  4. Review server access logs for XSS probe patterns
    Examine web server access logs (Apache/Nginx) for 404 requests where the requested URI contains patterns like <script, javascript:, or onerror= that target the vulnerable endpoint.
    Affected if Logs show unauthenticated requests with XSS payloads in the URI prior to admin access.
  5. Test admin 404 page for script execution
    As an administrator, access the WP Meta SEO 404 & Redirects admin page with a clean browser session and observe whether unexpected JavaScript executes or console errors appear.
    Affected if The admin 404 page renders stored content that executes arbitrary JavaScript.

A user is affected if WP Meta SEO plugin is installed with an unpatched version, the 404 & Redirects feature is enabled, and the database contains or the site has logged malicious XSS payloads in URI/host fields.

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

Update to a patched version of WP Meta SEO. Until then, disable the plugin or implement web application firewall rules to block malicious requests with XSS payloads in the URI.

Recommended fix Moderate confidence

Upgrade to the latest available version of WP Meta SEO (version higher than 4.5.18)

  1. 1. Navigate to the WordPress admin dashboard
  2. 2. Go to Plugins > Installed Plugins
  3. 3. Locate the 'WP Meta SEO' plugin
  4. 4. Check the current version number (should be 4.5.18 or lower)
  5. 5. If an update is available, click 'Update Now' to install the latest version
  6. 6. Alternatively, download the latest version from the WordPress plugin repository and upload it manually via Plugins > Add New > Upload Plugin
  7. 7. After updating, verify the plugin is active and functioning correctly

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

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,390
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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-2026-9643 in production — separate from our analysis above.

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