---
id: CVE-2026-55825
title: Contao is an Open Source CMS
summary: >-
  Contao is an Open Source CMS. In versions 5.7.0 through 5.7.6, an
  authenticated backend user who can access one job can request an attachment
  identifier containing ../ segments and make the job attachment download
  endpoint read a file fr…
severity: low
cvss: 3.1
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N'
cwe:
  - CWE-22
published: '2026-07-31'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T20:51:43.490'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-55825'
references:
  - url: 'https://github.com/contao/contao/security/advisories/GHSA-grm4-wm43-9jh5'
    label: security-advisories@github.com
tags:
  - nvd
epss: 0.00209
epssPercentile: 0.11321
ingestedAt: '2026-08-02T00:16:16.358Z'
---

## Overview

Contao is an Open Source CMS. In versions 5.7.0 through 5.7.6, an authenticated backend user who can access one job can request an attachment identifier containing ../ segments and make the job attachment download endpoint read a file from another job directory inside var/job-attachments. The controller authorizes only the jobUuid route parameter. The later attachment lookup joins that authorized job UUID with the attacker-controlled identifier, then passes the combined path to the virtual filesystem. VirtualFilesystem::resolve() canonicalizes the whole path and only rejects paths that escape the filesystem mount, so authorized-job/../victim-job/debug_log.csv becomes victim-job/debug_log.csv. This is a cross-job authorization bypass for known job attachment paths. It is not a practical brute-force against unknown jobs because job directories are UUID v4 values.

## Remediation

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