CVE-2026-88418

High

Description

CMSimple 5.24 ships with CSRF protection disabled by default, which turns csrfProtection() into a no-op on every state-changing admin request, and it does not send the csrf_token hidden field in admin forms. Because administrator authentication is cookie-only and no CSRF token is enforced, an unauthenticated attacker can induce a logged-in administrator's browser to issue a forged content-save request with a text payload containing a scripting marker. The marker is stored verbatim into content/content.php; on every subsequent page view evaluate_cmsimple_scripting() (functions.php) executes the marker body with PHP eval() — for all visitors, including unauthenticated ones. This yields persistent remote code execution on the web server.

SeverityHigh
CVSS8.8
Exploit probability—
ProductCMSimple
PublishedSep 22, 2026
First seenSep 22, 2026

How to fix

Sources list no fixed version or patch link for this vulnerability.

Affected products

ProductAffected versionsFixed in
CMSimple5.24—

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