MaxSite CMS — CVE-2026-70553 (Critical)

Date Aug 4, 2026

Type Vendor advisory

Signal Critical vendor advisory

Vendor / Product MaxSite · CMS

CVE CVE-2026-70553

Critical vendor advisory CVE-2026-70553

Summary

MaxSite CMS contains a remote code execution vulnerability that allows unauthenticated attackers to inject arbitrary PHP code into the application configuration file by submitting crafted POST requests to the install endpoint after installation is complete. Attackers can supply a malicious db_dbprefix value containing a single quote to break out of a PHP string literal in application/config/database.php, appending attacker-controlled PHP statements that are executed by the web server on every subsequent request, resulting in persistent unauthenticated remote code execution as the web-server pr

Why it matters

This CVE carries a CRITICAL severity rating (CVSS 9.8) in MaxSite CMS. Patch or mitigate promptly.

Operator check

Review CVE-2026-70553 in your asset inventory. Apply patches per vendor guidance and verify CMS is not exposed. CVSS score: 9.8.

Sources

NVD — CVE-2026-70553 Source reference Source reference

PatchBrief uses public sources. It does not scan environments, verify exposure, or replace vendor guidance.

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