CVE-2026-9643
HIGHThe 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…
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).
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of the affected component has shipped for CVE-2026-9643 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-9643 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-9643. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-9643 in your dependencies?
O3 detects CVE-2026-9643 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.