{"id":"GHSA-p68c-rmfh-j48h","aliases":["CVE-2026-30662"],"title":"ConcreteCMS is vulnerable to Denial of Service During Bulk Downloads","titleSource":"OSV","descriptionSource":"OSV","declaredSeverity":"MODERATE","description":"ConcreteCMS v9.4.7 contains a Denial of Service (DoS) vulnerability in the File Manager component. The 'download' method in 'concrete/controllers/backend/file.php' improperly manages memory when creating zip archives. It uses 'ZipArchive::addFromString' combined with 'file_get_contents', which loads the entire content of every selected file into PHP memory. An authenticated attacker can exploit this by requesting a bulk download of large files, triggering an Out-Of-Memory (OOM) condition that causes the PHP-FPM process to terminate (SIGSEGV) and the web server to return a 500 error.","severity":"medium","score":6.5,"published":"2026-03-24T15:30:29.000Z","modified":"2026-03-26T18:56:22.556Z","withdrawn":false,"knownExploited":false,"affected":[{"ecosystem":"Packagist","name":"concrete5/concrete5","sources":[{"name":"OSV · GHSA-p68c-rmfh-j48h","url":"https://osv.dev/vulnerability/GHSA-p68c-rmfh-j48h"}],"ranges":[{"events":[{"introduced":"0"},{"last_affected":"9.4.7"}],"type":"ECOSYSTEM"}],"versions":["8.0","8.0.1","8.0.2","8.0.3","8.1.0","8.2.0","8.2.0RC2","8.2.1","8.3.0","8.3.1","8.3.2","8.4.0","8.4.0RC3","8.4.0RC4","8.4.1","8.4.2","8.4.3","8.4.4","8.4.5","8.5.0","8.5.0RC1","8.5.0RC2","8.5.1","8.5.10","8.5.11","8.5.12","8.5.13","8.5.14","8.5.15","8.5.16","8.5.17","8.5.18","8.5.19","8.5.2","8.5.20","8.5.21","8.5.3","8.5.4","8.5.5","8.5.6","8.5.6RC1","8.5.7","8.5.8","8.5.9","9.0.0","9.0.0RC1","9.0.0RC3","9.0.0RC4","9.0.1","9.0.2","9.1.0","9.1.1","9.1.2","9.1.3","9.2.0","9.2.0RC2","9.2.1","9.2.2","9.2.3","9.2.4","9.2.5","9.2.6","9.2.7","9.2.8","9.2.9","9.3.0","9.3.1","9.3.2","9.3.3","9.3.4","9.3.5","9.3.6","9.3.7","9.3.8","9.3.9","9.4.0","9.4.0RC1","9.4.0RC2","9.4.1","9.4.2","9.4.3","9.4.4","9.4.5","9.4.6","9.4.7"],"fixed":[]}],"sourceAffected":[],"references":["https://nvd.nist.gov/vuln/detail/CVE-2026-30662","https://github.com/concretecms/concretecms","https://wang1rrr.github.io/2026/02/11/CVE-Report-ConcreteCMS-DoS"],"sources":[{"name":"OSV","id":"GHSA-p68c-rmfh-j48h","modified":"2026-03-26T18:56:22.556084Z","url":"https://osv.dev/vulnerability/GHSA-p68c-rmfh-j48h"}],"assessments":[{"source":"OSV","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":6.5}],"products":[],"remediation":[],"kev":{"status":"not-listed","checkedAt":"2026-10-29T00:30:33.731Z"},"coverage":[{"source":"NVD","status":"not-checked"},{"source":"GHSA","status":"not-checked"},{"source":"EUVD","status":"not-checked"},{"source":"EPSS","status":"not-checked"}],"evidence":[]}