---
id: CVE-2026-107848
title: Contao is an Open Source CMS
summary: >-
  Contao is an Open Source CMS. From version 4.0.0 until 5.3.50 and 5.7.12,
  RequestTokenListener validates REQUEST_TOKEN only for POST requests, while the
  declarative GET guard runs only when an act parameter is present. Backend
  actions di…
severity: low
cvss: 3.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N'
cwe:
  - CWE-352
vendor: contao
product: contao/core-bundle
affected:
  - 'contao/core-bundle >= 4.0.0, < 5.3.50'
  - 'contao/core-bundle >= 5.4.0-RC1, < 5.7.12'
patched:
  - contao/core-bundle 5.3.50
  - contao/core-bundle 5.7.12
published: '2026-10-09'
updated: '2026-10-09'
sourceUpdated: '2026-10-09T21:17:02.617'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-107848'
references:
  - url: >-
      https://github.com/contao/contao/commit/34dd27ee6739f10568d3d95d8784862255c925b4
    label: security-advisories@github.com
  - url: 'https://github.com/contao/contao/releases/tag/5.7.12'
    label: security-advisories@github.com
  - url: 'https://github.com/contao/contao/security/advisories/GHSA-9ff2-p842-45wq'
    label: security-advisories@github.com
  - url: 'https://github.com/advisories/GHSA-9ff2-p842-45wq'
tags:
  - nvd
  - ghsa
  - composer
aliases:
  - GHSA-9ff2-p842-45wq
ecosystem: composer
ingestedAt: '2026-10-09T21:12:42.325Z'
---

## Overview

Contao is an Open Source CMS. From version 4.0.0 until 5.3.50 and 5.7.12, RequestTokenListener validates REQUEST_TOKEN only for POST requests, while the declarative GET guard runs only when an act parameter is present. Backend actions dispatched through the key parameter can therefore execute without a CSRF token when an authenticated backend user loads an attacker-controlled URL. Reachable actions remain limited to modules available to that user, and the advisory demonstrates destructive or state-changing actions rather than privilege escalation. This issue is fixed in versions 5.3.50 and 5.7.12.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-107848)

Affected packages:

- `contao/core-bundle >= 4.0.0, < 5.3.50`
- `contao/core-bundle >= 5.4.0-RC1, < 5.7.12`

Patched in:

- `contao/core-bundle 5.3.50`
- `contao/core-bundle 5.7.12`

Source: https://github.com/advisories/GHSA-9ff2-p842-45wq