CVE-2026-55573

e107 is a content management system (CMS). Prior to 2.3.7, install.php decodes the attacker-controlled previous steps POST parameter and passes it to unserialize() at file scope and again in the e install constructor without restricting allowed classes. The installer remains accessible after a normal installation, and a crafted object graph using the bundled GuzzleHttpPsr7PumpStream class can flow through paths.hash into site path, where string coercion invokes an attacker-controlled callable. An unauthenticated attacker who can reach install.php can therefore execute arbitrary PHP functions with the web server process's privileges, leading to full server compromise. This issue is fixed in version 2.3.7.