Riskcovery

CVE-2026-104890

Kunstmaan CMS: MediaBundle extension blacklist bypass allows authenticated administrators to upload executable PHP files leading to remote code execution

State
Published
Severity
7.2 High
Published
Oct 5, 2026
Updated
Oct 7, 2026
Reserved
Oct 2, 2026

Read the record on cve.org

Description

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.

Scores

CVSSScoreVectorSource
3.17.2 HighCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:HGitHub_M

Weaknesses

  • CWE-434 Unrestricted Upload of File with Dangerous Type

Affected Products

ProductVersions
KunstmaanBundlesCMSKunstmaan
  • < 7.3.1Affected
bundles-cmskunstmaan
  • < 7.3.1Affected
media-bundlekunstmaan
  • < 7.3.1Affected

References

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