High severity · published Jun 24, 2026
CVE-2026-9643
WP Meta SEO <= 4.5.18 - Unauthenticated Stored Cross-Site Scripting via REQUEST_URI in 404 Logging
7.2
CVSS
0.4%
EPSS
No
On KEV
Description
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`).
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 36% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
WM
WP Meta SEO · joomunited
through 4.5.18 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-9643
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-9643
plugins.trac.wordpress.org
https://plugins.trac.wordpress.org/browser/wp-meta-seo/tags/4.5.18/inc/class.metaseo-broken-link-table.php#L894
plugins.trac.wordpress.org
https://plugins.trac.wordpress.org/browser/wp-meta-seo/tags/4.5.18/wp-meta-seo.php#L1135
plugins.trac.wordpress.org
https://plugins.trac.wordpress.org/browser/wp-meta-seo/tags/4.5.18/wp-meta-seo.php#L1171
plugins.trac.wordpress.org
https://plugins.trac.wordpress.org/changeset?old_path=/wp-meta-seo/tags/4.5.12&new_path=/wp-meta-seo/tags/4.5.13
ti.wordfence.io
https://ti.wordfence.io/vulnerabilities/ca91e41d-b728-4eb0-86d5-043813d8c2c1
www.wordfence.com
https://www.wordfence.com/threat-intel/vulnerabilities/id/beceb218-34bf-4571-a07b-939abc7ead8e?source=cve
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