{"id":"CVE-2026-104890","state":"PUBLISHED","title":"Kunstmaan CMS: MediaBundle extension blacklist bypass allows authenticated administrators to upload executable PHP files leading to remote code execution","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.","publishedAt":"2026-10-05T15:46:21.959Z","updatedAt":"2026-10-07T20:50:50.492Z","severity":{"score":7.2,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["Kunstmaan KunstmaanBundlesCMS","kunstmaan bundles-cms","kunstmaan media-bundle"],"affected":[{"vendor":"Kunstmaan","product":"KunstmaanBundlesCMS","versions":[{"version":"< 7.3.1","status":"affected"}]},{"vendor":"kunstmaan","product":"bundles-cms","versions":[{"version":"< 7.3.1","status":"affected"}]},{"vendor":"kunstmaan","product":"media-bundle","versions":[{"version":"< 7.3.1","status":"affected"}]}],"references":["https://github.com/Kunstmaan/KunstmaanBundlesCMS/security/advisories/GHSA-p279-5wcv-45vq","https://github.com/Kunstmaan/KunstmaanBundlesCMS/commit/1bbdfdeac8e7e91506b1a9271360b9b68d7690d3","https://github.com/Kunstmaan/KunstmaanBundlesCMS/releases/tag/7.3.2"],"weaknesses":["CWE-434"],"ingestedAt":"2026-10-29T20:10:23.711Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/104xxx/CVE-2026-104890.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-104890","state":"PUBLISHED","datePublished":"2026-10-05T15:46:21.959Z","dateUpdated":"2026-10-07T20:50:50.492Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-10-02T14:59:11.775Z"},"containers":{"cna":{"title":"Kunstmaan CMS: MediaBundle extension blacklist bypass allows authenticated administrators to upload executable PHP files leading to remote code execution","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"Kunstmaan","product":"KunstmaanBundlesCMS","versions":[{"version":"< 7.3.1","status":"affected"}]},{"vendor":"kunstmaan","product":"bundles-cms","versions":[{"version":"< 7.3.1","status":"affected"}]},{"vendor":"kunstmaan","product":"media-bundle","versions":[{"version":"< 7.3.1","status":"affected"}]}],"references":[{"url":"https://github.com/Kunstmaan/KunstmaanBundlesCMS/security/advisories/GHSA-p279-5wcv-45vq","name":"https://github.com/Kunstmaan/KunstmaanBundlesCMS/security/advisories/GHSA-p279-5wcv-45vq","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/Kunstmaan/KunstmaanBundlesCMS/commit/1bbdfdeac8e7e91506b1a9271360b9b68d7690d3","name":"https://github.com/Kunstmaan/KunstmaanBundlesCMS/commit/1bbdfdeac8e7e91506b1a9271360b9b68d7690d3","tags":["x_refsource_MISC"]},{"url":"https://github.com/Kunstmaan/KunstmaanBundlesCMS/releases/tag/7.3.2","name":"https://github.com/Kunstmaan/KunstmaanBundlesCMS/releases/tag/7.3.2","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":7.2,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"HIGH","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-434","lang":"en","description":"CWE-434: Unrestricted Upload of File with Dangerous Type","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-10-05T15:46:21.959Z"},"source":{"advisory":"GHSA-p279-5wcv-45vq","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-07T20:50:41.475759Z","id":"CVE-2026-104890","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-07T20:50:50.492Z"}}]}}}