CVE-2026-54611

InstantCMS has Remote Code Execution in package installer

Published Sep 8, 2026 CVSS 3.1 · 5.5 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Instantcms
Instantcms icms2
Vendors & Products Instantcms
Instantcms icms2
Type Values Removed Values Added
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.
Title InstantCMS has Remote Code Execution in package installer
Weaknesses CWE-434
CWE-94
References
Metrics cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Sep 9, 2026, 5:39 PM
Reserved
Jun 15, 2026, 7:45 PM
Status
Deferred
Published
Sep 8, 2026, 6:17 PM
Modified
Sep 9, 2026, 6:16 PM