CVE-2026-54611

Summary

InstantCMS is a free and open source content management system. Versions prior to 2.18.2 have a Remote Code Execution (RCE) issue that allows remote authenticated attackers to execute any PHP code via the component installer. It is possible to upload a malicious component into the server, however, it won't be installed, but upload files will be executed. Normally all php files in upload folder are not executed, however, by uploading custom .htaccess it becomes possible. Version 2.18.2 contains a fix.

Affected Software

VendorProductVersion RangeStatus
instantsofticms2< 2.18.2affected

Weaknesses

  • CWE-94: CWE-94: Improper Control of Generation of Code ('Code Injection')
  • CWE-434: CWE-434: Unrestricted Upload of File with Dangerous Type

References