EUVD-2026-31343
GHSA-g7xp-jf3x-wcx4
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A01:2025 - Broken Access Control
ASVS 5.0
V8 - Authorization Authorization logic validation
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 – May 21, 2026
Privilege escalation in Concrete CMS 9.5.0 and earlier allows authenticated users with access to the bulk user assignment dashboard to add arbitrary accounts to the Administrators group and remove existing admins, effectively hijacking site control. The flaw stems from missing authorization checks in bulk_user_assignment.php and was disclosed with a vendor-assigned CVSS v4.0 score of 7.5. No public exploit identified at time of analysis, and the issue is not present in CISA KEV.
Affected VersionsENISA
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 2 packages in composer, euvd
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Primary rating from Vendor (ff5b8ace-8b95-4078-9743-eac1ca5451de) · only source for this CVE.
CVSS VectorVendor: ff5b8ace-8b95-4078-9743-eac1ca5451de
DescriptionCVE.org
Concrete CMS 9.5.0 and below is vulnerable to missing authorization in the bulk_user_assignment.php which can lead to privilege escalation to Administrative Group. Any authenticated user with access to the bulk user assignment dashboard page can add any user email to any group and can remove legitimate admins. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 7.5 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks Vincent55 for reporting.
Executive ViewAI
Concrete CMS 9.5.0 and earlier contain a privilege escalation vulnerability affecting authenticated users with bulk user assignment dashboard access. These users can manipulate administrative accounts and hijack complete site control; no public exploit has been identified at time of analysis. Organizations running affected versions face administrative account takeover risk if user credentials are compromised.
24 hours: Audit all users with bulk user assignment dashboard access and restrict permissions to essential administrators only; review recent changes to admin accounts. 7 days: Disable the bulk user assignment feature if not actively required; implement access controls requiring multi-party approval for admin account modifications. 30 days: Monitor vendor for patch availability; upgrade when available; maintain audit logging of all administrative changes.
No vendor-released patch identified at time of analysis. Restrict bulk user assignment dashboard access to a minimal set of trusted administrators; disable the feature if operationally feasible; implement comprehensive audit logging for admin account modifications; require multi-factor authentication for all administrative access.
Threat Intelligence Overview
NVD
CVE.org
EPSS
Vulnrichment
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
Authentication bypass attacks exploit flaws in the verification mechanisms that control access to systems and applications.
Privilege escalation occurs when an attacker leverages flaws in access control mechanisms to gain permissions beyond what they were originally granted.
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