Vulnerability · Published Sep 8, 2026 · Assigned by GitHub_M
CVE-2026-54611InstantCMS has Remote Code Execution in package installer
Medium 5.5
In plain English
A medium-severity code injection in icms2 from instantsoft. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 52% of all known vulnerabilities).
Official description
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 products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| instantsoft | icms2 | < 2.18.2 |
Weakness: CWE-94, CWE-434 · Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:H