GitHub Advisoryadvisory · Packagist

GHSA-p68c-rmfh-j48h ConcreteCMS is vulnerable to Denial of Service During Bulk Downloads

MEDIUM Published 2026-03-24 Modified 2026-03-26 Official page ↗
Aliases
CVE-2026-30662
Ecosystem
Packagist
Packages
concrete5/concrete5
Severity
Moderate
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weaknesses
CWE-770
Reviewed
2026-03-26

Affected packages

• Packagist concrete5/concrete5: <= 9.4.7 (no fix yet)

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.

Related

Alias · CVE (1)

  • CVE-2026-30662 ConcreteCMS v9.4.7 contains a Denial of Service (DoS) vulnerability in the File Manager component. vulnerability

Weakness · CWE (1)

  • CWE-770 Allocation of Resources Without Limits or Throttling weakness

References