---
id: CVE-2026-18422
title: >-
  Concrete CMS before 9.5.3 did not enforce a destination-side authorization
  check and did not validate a CSRF token in the multilingual page assignment
  backend action (Backend\Page\Multilingual::assign)
summary: >-
  Concrete CMS before 9.5.3 did not enforce a destination-side authorization
  check and did not validate a CSRF token in the multilingual page assignment
  backend action (Backend\Page\Multilingual::assign). As a result, an
  authenticated user…
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:H'
cwe:
  - CWE-862
vendor: concretecms
product: concrete_cms
affected:
  - concrete_cms < 9.5.3
patched:
  - concrete_cms 9.5.3
published: '2026-09-15'
updated: '2026-09-21'
sourceUpdated: '2026-09-21T17:50:08.090'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-18422'
references:
  - url: >-
      https://documentation.concretecms.org/developers/introduction/version-history/953-release-notes
    label: ff5b8ace-8b95-4078-9743-eac1ca5451de
tags:
  - nvd
  - cve.org
  - score-dispute
epss: 0.00443
epssPercentile: 0.35766
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-15T19:43:11.355490Z'
scores:
  nvd: 6.5
  cna: 2.1
ingestedAt: '2026-09-15T19:42:58.818Z'
---

## Overview

Concrete CMS before 9.5.3 did not enforce a destination-side authorization check and did not validate a CSRF token in the multilingual page assignment backend action (Backend\Page\Multilingual::assign). As a result, an authenticated user who held the Edit Page Multilingual Settings permission on a single page could bind an arbitrary page in another locale as that source page's translation, and could delete legitimate translation pairs maintained by other editors, altering public-facing language routing across the site. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 2.1 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N. Thanks Winston Crooker for reporting.

## Affected

- `concrete_cms < 9.5.3`

## Remediation

Upgrade past the affected range:

- `concrete_cms 9.5.3`