How severe is CVE-2026-30662?

CVE-2026-30662 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-30662 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (21st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-30662?

CVE-2026-30662 affects Concretecms Concrete Cms. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-30662?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-30662 have an EU (EUVD) identifier?

Yes. CVE-2026-30662 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-14895.

When was CVE-2026-30662 published?

CVE-2026-30662 was published on 2026-03-24 and last updated on 2026-06-17.

CVE-2026-30662

CVE-2026-30662 is a medium-severity vulnerability in Concretecms Concrete Cms with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-400.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
EPSS exploit prediction: 0% (21st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-14895
Weakness: CWE-400
Affected product: Concretecms Concrete Cms
Published: 2026-03-24
Last modified: 2026-06-17

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.

Frequently asked questions

What is 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.
How severe is CVE-2026-30662?: CVE-2026-30662 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-30662 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (21st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-30662?: CVE-2026-30662 affects Concretecms Concrete Cms. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-30662?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-30662 have an EU (EUVD) identifier?: Yes. CVE-2026-30662 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-14895.
When was CVE-2026-30662 published?: CVE-2026-30662 was published on 2026-03-24 and last updated on 2026-06-17.

References

https://wang1rrr.github.io/2026/02/11/CVE-Report-ConcreteCMS-DoS/

Affected products (1)

cpe:2.3:a:concretecms:concrete_cms:9.4.7:*:*:*:*:*:*:*

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