---
id: CVE-2026-81912
title: >-
  Concrete CMS before 9.5.3 is vulnerable to Cross-Site Request Forgery in the
  Move Multiple Groups feature
summary: >-
  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, s…
severity: medium
cvss: 5.7
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N'
cwe:
  - CWE-352
vendor: concretecms
product: concrete_cms
affected:
  - concrete_cms < 9.5.4
patched:
  - concrete_cms 9.5.4
published: '2026-09-11'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T20:18:47.767'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-81912'
references:
  - url: >-
      https://documentation.concretecms.org/developers/introduction/version-history/953-release-notes
    label: ff5b8ace-8b95-4078-9743-eac1ca5451de
tags:
  - nvd
  - cve.org
epss: 0.00188
epssPercentile: 0.07436
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-11T19:36:20.590270Z'
ingestedAt: '2026-09-14T00:35:28.533Z'
---

## Overview

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.

## Affected

- `concrete_cms < 9.5.4`

## Remediation

Upgrade past the affected range:

- `concrete_cms 9.5.4`