CVE-2026-30662

ConcreteCMS Bulk Download OOM Denial of Service

Published Mar 24, 2026 CVSS 3.1 · 6.5 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-p68c-rmfh-j48h ConcreteCMS is vulnerable to Denial of Service During Bulk Downloads
History
Type Values Removed Values Added
Title ConcreteCMS Bulk Download OOM Denial of Service
Type Values Removed Values Added
First Time appeared Concretecms
Concretecms concrete Cms
CPEs cpe:2.3:a:concretecms:concrete_cms:9.4.7:*:*:*:*:*:*:*
Vendors & Products Concretecms
Concretecms concrete Cms
Type Values Removed Values Added
Weaknesses CWE-400
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
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.
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
mitre
Published
Updated
Mar 24, 2026, 6:49 PM
Reserved
Mar 4, 2026, 12:00 AM
Status
Modified
Published
Mar 24, 2026, 3:16 PM
Modified
Jun 17, 2026, 10:32 AM