Instituto Nacional de ciberseguridad. Sección Incibe
Instituto Nacional de Ciberseguridad. Sección INCIBE-CERT

Go to Calendar     Go to Press Room     Go to Newsletters subscription

CVE-2026-81912

Severity CVSS v4.0:
MEDIUM
Type:
CWE-352 Cross-Site Request Forgery (CSRF)
Publication date:
11/09/2026
Last modified:
24/09/2026

Description

Concrete CMS before 9.5.3 is vulnerable to Cross-Site Request Forgery in the Move Multiple Groups feature. The dashboard/users/groups/bulkupdate/confirm() endpoint moved the selected group tree nodes without validating an action token, so a state-changing group move could be processed for an authenticated user who did not initiate it. Because relocating a group under a new parent causes that group's members to inherit the parent's permissions, a forged move can change effective authorization. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 5.7 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N. Thanks riodrwn for reporting.

Impact

Vector 4.0
CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N CVSS v4.0 Severity and Metrics:

Base Score: 5.70 MEDIUM
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

Attack Vector (AV): Network
Attack Complexity (AC): Low
Attack Requirements (AT): Present
Privileges Required (PR): High
User Interaction (UI): Passsive
Confidentiality (VC): High
Integrity (VI): None
Availability (VA): None
Confidentiality (SC): None
Integrity (SI): None
Availability (SA): None

Base Score 4.0
5.70
Severity 4.0
MEDIUM
Vector 3.x
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N CVSS v3.1 Severity and Metrics:

Base Score: 5.70 MEDIUM
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): Low
User Interaction (UI): Required
Scope (S): Unchanged
Confidentiality (C): High
Integrity (I): None
Availability (A): None

Base Score 3.x
5.70
Severity 3.x
MEDIUM

Vulnerable products and versions

CPE From Up to
cpe:2.3:a:concretecms:concrete_cms:*:*:*:*:*:*:*:* 9.5.4 (excluding)

To consult the complete list of CPE names with products and versions, see this page


References to Advisories, Solutions, and Tools