CVE-2026-9643 WP Meta SEO <= 4.5.18 - Unauthenticated Stored Cross-Site Scripting via REQUEST_URI in 404 Logging
Unauthenticated attackers can inject scripts via 404 logging that execute when administrators view the plugin's admin page.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-9643?
CVE-2026-9643 is a high-severity cross-site scripting vulnerability in joomunited WP Meta SEO, published on 24 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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`).
Weakness: CWE-79
Which versions are affected by CVE-2026-9643?
How do I fix CVE-2026-9643?
No fix has been published for CVE-2026-9643 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-9643 being exploited?
There is no known exploitation of CVE-2026-9643 in the wild and no public exploit code.
Sources
Also known as GHSA-qhjr-7q98-w4h3.