CVE-2026-1553
📋 TL;DR
This CVE describes an incorrect authorization vulnerability in Drupal Canvas that allows forceful browsing (unauthorized access to restricted functionality). It affects all Drupal Canvas installations from initial release through version 1.0.3. Attackers can bypass intended access controls to reach administrative or privileged functionality.
💻 Affected Systems
- Drupal Canvas
📦 What is this software?
Drupal Canvas by Drupal Canvas Project
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of the Drupal site through unauthorized administrative access, allowing content manipulation, user account takeover, or installation of malicious modules.
Likely Case
Unauthorized access to administrative interfaces leading to content modification, configuration changes, or privilege escalation for authenticated users.
If Mitigated
Limited impact with proper network segmentation and access controls, potentially allowing only information disclosure of restricted content.
🎯 Exploit Status
Exploitation requires some level of access to the Drupal site but can bypass authorization checks once authenticated.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.0.4
Vendor Advisory: https://www.drupal.org/sa-contrib-2026-006
Restart Required: No
Instructions:
1. Backup your Drupal site. 2. Update Drupal Canvas module to version 1.0.4 via Drupal's update manager or Composer. 3. Clear Drupal caches. 4. Verify the update was successful.
🔧 Temporary Workarounds
Disable Canvas Module
linuxTemporarily disable the vulnerable Canvas module until patching is possible
drush pm-disable canvas
drush cr
Restrict Access via .htaccess
allAdd access restrictions to Canvas module directories
# Add to .htaccess in canvas module directory:
Order deny,allow
Deny from all
🧯 If You Can't Patch
- Implement strict network access controls to limit who can reach the Drupal administrative interface
- Enable detailed logging and monitoring for unauthorized access attempts to Canvas functionality
🔍 How to Verify
Check if Vulnerable:
Check Drupal's module status page or run: drush pm-list | grep canvasCheck Version:
drush pm-list --fields=version | grep canvasVerify Fix Applied:
Confirm Canvas module version is 1.0.4 or higher via Drupal admin interface or: drush pm-list --fields=version | grep canvas📡 Detection & Monitoring
Log Indicators:
- Unauthorized access attempts to Canvas module paths
- 403 errors followed by successful 200 responses to restricted Canvas endpoints
Network Indicators:
- Unusual patterns of requests to /canvas/* paths from non-admin users
SIEM Query:
source="drupal_access.log" AND (uri="/canvas/*" OR uri="/admin/canvas/*") AND (response=200 OR response=403) AND user_agent NOT IN admin_user_agents