CVE-2026-30662 json
ConcreteCMS is vulnerable to Denial of Service During Bulk Downloads
published 2026-03-24 7 mo ago modified 2026-06-17 4 mo ago also GHSA-p68c-rmfh-j48h , EUVD-2026-14895
- cvss
- 6.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 22%
- public exploits
- 0
- none known
Summary
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.
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- partial
- Assessed
- 7 mo ago
Exploit prediction
0.30% chance of exploitation in the next 30 days, higher than 22% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- wang1rrr.github.io https://wang1rrr.github.io/2026/02/11/CVE-Report-ConcreteCMS-DoS/ referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CISA ADP | 3.1 | 6.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| NVD | 3.1 | 6.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| CNA | 3.1 | 6.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| GitHub | 3.1 | 6.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| packagist | concrete5/concrete5 | <=9.4.7 |
no fix listed |
Classification
References
-
wang1rrr.github.io
/2026/02/11/CVE-Report-ConcreteCMS-DoS/
exploit, third-party-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2026-30662
advisory
-
github.com
/concretecms/concretecms
package
-
wang1rrr.github.io
/2026/02/11/CVE-Report-ConcreteCMS-DoS
web
Sources
- CVE List CVE-2026-30662
- GitHub Advisory GHSA-p68c-rmfh-j48h
- NVD CVE-2026-30662
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