EUVD-2026-78830
GHSA-7hmf-f7jv-m4xw
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A01:2025 - Broken Access Control
ASVS 5.0
V8 - Authorization Authorization checks on every request
MITRE ATT&CK
1 technique across 1 tactic: Privilege Escalation The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
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Alert meAnalysisAIv1 – Sep 15, 2026
Unauthenticated user enumeration in Concrete CMS 9.0.0 through 9.5.2 allows any anonymous visitor to dump the complete backend account list — including internal user IDs, usernames and email addresses of every administrator and the super-administrator (user ID 1) — by sending an empty search to the /ccm/system/user/autocomplete endpoint and paginating the results. The endpoint enforces only a CSRF-style token that is bound to the selector's display options rather than to caller identity, and that token is handed out to anonymous visitors, so there is no authentication or privilege barrier to clear. No password hashes or session material leak, but the disclosed email and account inventory is a ready-made target list for credential stuffing, phishing and password-spray campaigns against named admins; no public exploit code and no CISA KEV entry are present in the supplied intelligence.
Affected VersionsENISA
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in euvd
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Severity by source
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
Primary rating from Vendor (ConcreteCMS) · only source for this CVE.
CVSS VectorVendor: ConcreteCMS
DescriptionCVE.org
Concrete CMS 9 (9.0.0 through 9.5.2) does not perform an authorization check on the user selector autocomplete endpoint (/ccm/system/user/autocomplete), which backs the "Preview as User" panel and other user-selector components. The endpoint validates only a CSRF-style access token that is bound to the selector's display options rather than to the caller's identity or permissions, and that token is issued to anonymous visitors because the selector renders without an authorization check. Because an empty query resolves to a match-all filter, an unauthenticated attacker can submit an empty search and paginate the results to enumerate every backend account, disclosing the internal user ID, username, and email address of all administrative users, including the super-administrator (user ID 1). No password hashes or session material are disclosed The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 8.7 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N. Thanks thirtythree and YesWeHack for reporting.
Threat Intelligence Overview
NVD
CVE.org
EPSS
VulDB
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Cross-Site Request Forgery exploits the automatic credential inclusion behavior of web browsers.
Authentication bypass attacks exploit flaws in the verification mechanisms that control access to systems and applications.
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Exploit-DB