Resource exhaustion in Concretecms Concrete Cms
CVE-2026-30662
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.
Vulnerability class: DoS (Denial of Service)
EPSS: 0.003 (21.1th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Concretecms Concrete_cms — versions 9.4.7
- N/a — versions n/a
Weakness classification (CWE)
References
- cve@mitre.org (Exploit, Third Party Advisory)
Frequently asked questions
- What is CVE-2026-30662?
- CVE-2026-30662 is a medium-severity vulnerability in Concretecms Concrete Cms, classified under Uncontrolled Resource Consumption. CVSS score: 6.5/10. Published 2026-03-24.
- How severe is CVE-2026-30662?
- Medium severity. CVSS v3 base score is 6.5 out of 10.