{"id":"CVE-2026-53599","summary":"Redaxo has a Mediapool isAllowedExtension bypass via multi-segment filename that leads to authenticated RCE on Apache mod_php multi-extension handlers","details":"REDAXO is a PHP-based content management system. From 5.18.2 until 5.21.1, rex_mediapool::isAllowedExtension in redaxo/src/addons/mediapool/lib/mediapool.php lets an authenticated backend user with media[upload] permission upload a JPEG/PHP polyglot named shell.php.any.jpg, which web servers with multi-extension PHP handlers can execute as the web-server user. This issue is fixed in version 5.21.1.","aliases":["GHSA-98pp-vccm-qm25"],"modified":"2026-08-02T03:47:49.623470848Z","published":"2026-07-31T19:43:15.663Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-434"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53599.json"},"references":[{"type":"WEB","url":"https://github.com/redaxo/core/releases/tag/5.21.1"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53599.json"},{"type":"ADVISORY","url":"https://github.com/redaxo/core/security/advisories/GHSA-98pp-vccm-qm25"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53599"},{"type":"FIX","url":"https://github.com/redaxo/core/commit/462e36896bb65d292ba22d711044c23c9cfb0340"},{"type":"FIX","url":"https://github.com/redaxo/core/pull/6538"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/redaxo/core","events":[{"introduced":"fdd41fcc9acb3cddb80b3f4098c820709193f457"},{"fixed":"462e36896bb65d292ba22d711044c23c9cfb0340"},{"fixed":"a70ea49624f291319cfe66dd9b53200e25cd3bcd"}],"database_specific":{"extracted_events":[{"introduced":"5.18.2"},{"fixed":"5.21.1"}],"source":["AFFECTED_FIELD","REFERENCES"]}}],"versions":["5.21.0","5.21.0-beta1","5.20.2","5.20.1","5.20.0","5.19.0","5.18.3","5.18.2"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53599.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}