CVE-2026-21861

Name of the Vulnerable Software and Affected Versions baserCMS versions prior to 5.2.3

Description baserCMS contains an OS command injection flaw in its core update functionality. An authenticated administrator can execute arbitrary OS commands on the server because user-controlled input is passed directly to the exec() function without sufficient validation or escaping. This design issue allows for Remote Code Execution (RCE), enabling the retrieval of server information, reading or writing arbitrary files, and accessing application configuration data such as database credentials.

API Endpoints: /baser/admin/baser-core/plugins/get core update Vulnerable Parameters or Variables: php Function Names: PluginsController::get core update(), PluginsService::getCoreUpdate(), and exec()

Recommendations Update baserCMS to version 5.2.3. As a temporary mitigation, restrict access to the /baser/admin/baser-core/plugins/get core update endpoint to minimize the risk of exploitation.