How severe is CVE-2026-8236?

CVE-2026-8236 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity low, and availability none.

Is CVE-2026-8236 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (58th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-8236?

CVE-2026-8236 affects Concretecms Concrete Cms. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-8236?

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

Does CVE-2026-8236 have an EU (EUVD) identifier?

Yes. CVE-2026-8236 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-31347.

When was CVE-2026-8236 published?

CVE-2026-8236 was published on 2026-05-21 and last updated on 2026-07-23.

CVE-2026-8236

CVE-2026-8236 is a medium-severity vulnerability in Concretecms Concrete Cms with a CVSS 3.x base score of 4.3. 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-862.

Key facts

Severity: Medium (CVSS 3.x base score 4.3)
CVSS v4: 6.3
EPSS exploit prediction: 1% (58th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-31347
Weakness: CWE-862
Affected product: Concretecms Concrete Cms
Published: 2026-05-21
Last modified: 2026-07-23

Description

Concrete CMS 9.5.0 and below is vulnerable to IDOR combined with a missing authentication gate. The endpoint /ccm/system/dialogs/file/usage/{fID} accepts an integer file ID in the URL and returns internal site structure data (page IDs, versions, URL paths) to anyone who sends a GET request. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 6.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N. Thanks Winston Crooker for reporting.

Frequently asked questions

What is CVE-2026-8236?: Concrete CMS 9.5.0 and below is vulnerable to IDOR combined with a missing authentication gate. The endpoint /ccm/system/dialogs/file/usage/{fID} accepts an integer file ID in the URL and returns internal site structure data (page IDs, versions, URL paths) to anyone who sends a GET request. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 6.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N. Thanks Winston Crooker for reporting.
How severe is CVE-2026-8236?: CVE-2026-8236 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2026-8236 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (58th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-8236?: CVE-2026-8236 affects Concretecms Concrete Cms. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-8236?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-8236 have an EU (EUVD) identifier?: Yes. CVE-2026-8236 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-31347.
When was CVE-2026-8236 published?: CVE-2026-8236 was published on 2026-05-21 and last updated on 2026-07-23.

References

https://documentation.concretecms.org/9-x/developers/introduction/version-history/951-release-notes

Affected products (1)

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

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