CVE•Published 2026-05-21•Modified 2026-05-26•0 articles on news•6 live references•NVD data

CVE-2026-8205Concretecms · Concrete_cms

Vulnerability data via NVD (ingested)

CVSS v3.1

5.3

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

EPSS percentile

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Weaknesses (CWE)

CWE-425Direct Request ('Forced Browsing')

Description

Concrete CMS 9.5.0 and below is vulnerable to authorization bypass in the Calendar Block since action_get_events does not check canView on the calendar which results in restricted event details being disclosed. 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 lalalala5678 for reporting.

Timeline

Published 2026-05-21

Modified 2026-05-26

External references

NVD MITRE Exploit-DB GitHub PoC Sploitus VulnCheck

Search for exposed instances

Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).

Shodan · vuln tag0 hosts

vuln:CVE-2026-8205

Hosts Shodan has explicitly fingerprinted as vulnerable.

Shodan · product

product:"Concretecms Concrete Cms"

All exposed Concretecms Concrete Cms instances — cross-reference with the CVE's affected-version range.

Shodan · banner/body mention

http.html:"Concrete Cms"

HTTP body or banner mentions "Concrete Cms" — catches deploys Shodan didn't identify as a product.

More intel sources (5)

Shodan report

vuln:CVE-2026-8205