Concrete CMS before 9.5.3 is vulnerable to Cross-Site Request Forgery in the Move Multiple Groups feature. (CVE-2026-81912)
Concrete CMS versions before 9.5.3 have a Cross-Site Request Forgery (CSRF) vulnerability in the Move Multiple Groups feature. The affected endpoint does not validate an action token, allowing an authenticated user to be tricked into moving group nodes without their intent. This can alter group membership inheritance and change effective permissions. The vulnerability has a CVSS v4.0 base score of 5.7, indicating medium severity.
AI Analysis
Technical Summary
Concrete CMS prior to version 9.5.3 contains a CSRF vulnerability in the dashboard/users/groups/bulkupdate/confirm() endpoint. This endpoint processes requests to move multiple group tree nodes but lacks validation of an action token, enabling attackers to perform unauthorized state-changing operations on behalf of authenticated users. Since moving a group under a new parent causes members to inherit the parent's permissions, this can lead to unauthorized permission changes. The vulnerability was assigned CVE-2026-81912 and has a CVSS v4.0 score of 5.7.
Potential Impact
An attacker can exploit this vulnerability to trick an authenticated user into unknowingly moving groups within the CMS. This action changes group membership inheritance, potentially granting unauthorized permissions to users. The impact is a medium severity authorization change without direct data disclosure or system compromise.
Mitigation Recommendations
A fix is available in Concrete CMS version 9.5.3. Users should upgrade to version 9.5.3 or later to remediate this vulnerability. No other mitigation guidance is provided or necessary as the issue is resolved by the official patch.
Concrete CMS before 9.5.3 is vulnerable to Cross-Site Request Forgery in the Move Multiple Groups feature. (CVE-2026-81912)
Description
Concrete CMS versions before 9.5.3 have a Cross-Site Request Forgery (CSRF) vulnerability in the Move Multiple Groups feature. The affected endpoint does not validate an action token, allowing an authenticated user to be tricked into moving group nodes without their intent. This can alter group membership inheritance and change effective permissions. The vulnerability has a CVSS v4.0 base score of 5.7, indicating medium severity.
CVSS v4.0
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Concrete CMS prior to version 9.5.3 contains a CSRF vulnerability in the dashboard/users/groups/bulkupdate/confirm() endpoint. This endpoint processes requests to move multiple group tree nodes but lacks validation of an action token, enabling attackers to perform unauthorized state-changing operations on behalf of authenticated users. Since moving a group under a new parent causes members to inherit the parent's permissions, this can lead to unauthorized permission changes. The vulnerability was assigned CVE-2026-81912 and has a CVSS v4.0 score of 5.7.
Potential Impact
An attacker can exploit this vulnerability to trick an authenticated user into unknowingly moving groups within the CMS. This action changes group membership inheritance, potentially granting unauthorized permissions to users. The impact is a medium severity authorization change without direct data disclosure or system compromise.
Mitigation Recommendations
A fix is available in Concrete CMS version 9.5.3. Users should upgrade to version 9.5.3 or later to remediate this vulnerability. No other mitigation guidance is provided or necessary as the issue is resolved by the official patch.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-gpgr-mxq3-f5p5
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-81912"]
- Database Specific Severity
- MODERATE
- Cvss Version
- 4.0
Threat ID: 6aa4a02655bf5e2cf5a869c7
Added to database: 09/12/2026, 00:43:18 UTC
Last enriched: 09/12/2026, 01:18:28 UTC
Last updated: 09/12/2026, 01:18:28 UTC
Views: 2
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