---
id: CVE-2026-104890
title: >-
  Kunstmaan CMS is an open source content management system based on the Symfony
  framework
summary: >-
  Kunstmaan CMS is an open source content management system based on the Symfony
  framework. Prior to 7.3.2,
  src/Kunstmaan/MediaBundle/Helper/File/FileHandler.php performs the
  blacklisted_extensions check case-sensitively in FileHandler::ge…
severity: high
cvss: 7.2
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-434
vendor: Kunstmaan
product: KunstmaanBundlesCMS
affected:
  - KunstmaanBundlesCMS < 7.3.1
  - bundles-cms < 7.3.1
  - media-bundle < 7.3.1
published: '2026-10-05'
updated: '2026-10-05'
sourceUpdated: '2026-10-05T16:17:06.270'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-104890'
references:
  - url: >-
      https://github.com/Kunstmaan/KunstmaanBundlesCMS/commit/1bbdfdeac8e7e91506b1a9271360b9b68d7690d3
    label: security-advisories@github.com
  - url: 'https://github.com/Kunstmaan/KunstmaanBundlesCMS/releases/tag/7.3.2'
    label: security-advisories@github.com
  - url: >-
      https://github.com/Kunstmaan/KunstmaanBundlesCMS/security/advisories/GHSA-p279-5wcv-45vq
    label: security-advisories@github.com
tags:
  - nvd
  - cve.org
ingestedAt: '2026-10-05T16:25:58.410Z'
---

## Overview

Kunstmaan CMS is an open source content management system based on the Symfony framework. Prior to 7.3.2, src/Kunstmaan/MediaBundle/Helper/File/FileHandler.php performs the blacklisted_extensions check case-sensitively in FileHandler::getFilePath and lowercases the stored extension afterward. An authenticated backend user with media access can upload a mixed-case executable extension such as PHP that bypasses the check and is stored in the web-accessible media directory with an executable lowercase extension. The default blacklist also omits several server-executable extension types, allowing the same code-execution impact where the web server executes uploaded files. This issue is fixed in version 7.3.2.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.