Concrete Cms
CVE-2026-2994
MEDIUM
GHSA-6mxw-2vhf-42g5
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A01:2025 - Broken Access Control
ASVS 5.0
V3 - Web Frontend Security Anti-CSRF tokens, SameSite cookies
MITRE ATT&CK
1 technique across 1 tactic: Initial Access The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS 6.8 (MEDIUM). Attack vector: Network. Complexity: Low. Privileges required: High. User interaction: Required. Exploitation requires authentication. Public exploit/POC available. |
| Exploit ScenarioDerived | An attacker (requires authentication) could exploit this flaw, a security bypass since changes are saved prior to checking. |
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Alert meAnalysisAIv1 – Mar 12, 2026
Concrete CMS versions below 9.4.8 contain a cross-site request forgery vulnerability in the Anti-Spam Allowlist Group Configuration that allows authenticated administrators to modify security settings without valid CSRF token validation. An attacker with administrative privileges can exploit this to bypass security controls by manipulating the group_id parameter before token verification occurs. Public exploit code exists for this vulnerability, and a patch is available.
Earlier versions of this analysis (1)
Concrete CMS below version 9.4.8 is subject to CSRF by a Rogue Administrator using the Anti-Spam Allowlist Group Configuration via group_id parameter which can leads to a security bypass since changes are saved prior to checking the CSRF token. [CVSS 6.8 MEDIUM]
RemediationAI
A vendor patch is available — apply it immediately. Restrict network access to the affected service where possible.
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in composer
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
Classified as CWE-352 (Cross-Site Request Forgery (CSRF)). Affects the group_id component of Concrete Cms. Concrete CMS below version 9.4.8 is subject to CSRF by a Rogue Administrator using the Anti-Spam Allowlist Group Configuration via group_id parameter which can leads to a security bypass since changes are saved prior to checking the CSRF token. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 2.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks z3rco for reporting
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
Lifecycle Timeline
3DescriptionCVE.org
Concrete CMS below version 9.4.8 is subject to CSRF by a Rogue Administrator using the Anti-Spam Allowlist Group Configuration via group_id parameter which can leads to a security bypass since changes are saved prior to checking the CSRF token. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 2.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks z3rco for reporting
Executive ViewAI
Organizations using Concrete CMS below version 9.4.8 should be aware of notable risk from CVE-2026-2994, a cross-site request forgery vulnerability rated CVSS 6.8. Users could be tricked into performing unintended actions. Proof-of-concept code is publicly available. A patch is available and should be applied during regular vulnerability management.
Apply vendor patch. If patching is delayed: implement SameSite cookie attributes and anti-CSRF tokens.
Threat Intelligence Overview
NVD
CVE.org
EPSS
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.
Affected Products (CPE)CVE.org
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concrete5 8.1.0 places incorrect trust in the HTTP Host header during caching, if the administrator did not define a "ca
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Exploit-DB