InstantCMS has Remote Code Execution in package installer

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-54611
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-09-08 18:17:41 UTC
Updated2026-09-08 21:05:26 UTC
DescriptionInstantCMS 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.

Risk And Classification

Primary CVSS: v3.1 5.5 MEDIUM from [email protected]

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:H

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

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary5.5MEDIUMCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:H
3.1CNADECLARED5.5MEDIUMCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:H

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
High
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
High

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:H

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Instantsoft Icms2 affected < 2.18.2 Not specified

References

ReferenceSourceLinkTags
github.com/instantsoft/icms2/security/advisories/GHSA-vvgv-h28h-p2m5 [email protected] github.com
github.com/instantsoft/icms2/commit/44f3a9d04a3207c82cdc756599cbdf084a02... [email protected] github.com
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