CVE-2026-21626
📋 TL;DR
This vulnerability allows unauthorized access to forum post custom fields through JSON output, bypassing access control settings. It affects EasyDiscuss forum software users who have custom fields configured. Attackers can exploit this to view sensitive information they shouldn't have access to.
💻 Affected Systems
- EasyDiscuss
📦 What is this software?
Easydiscuss by Stackideas
⚠️ Risk & Real-World Impact
Worst Case
Complete exposure of all custom field data across all forum posts, including potentially sensitive user information, private discussions, or confidential data stored in custom fields.
Likely Case
Selective information disclosure where attackers can view custom field data from posts they shouldn't have access to, potentially revealing user details, preferences, or other metadata.
If Mitigated
Limited exposure if custom fields contain only non-sensitive information or if network segmentation prevents external access.
🎯 Exploit Status
Exploitation requires understanding of the forum structure and custom field implementation. Attackers need some level of access to the forum system.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Latest version from vendor
Vendor Advisory: https://stackideas.com/easydiscuss
Restart Required: No
Instructions:
1. Backup your EasyDiscuss installation and database. 2. Download the latest version from the vendor. 3. Replace affected files with patched versions. 4. Clear any caches. 5. Test functionality.
🔧 Temporary Workarounds
Disable JSON Output
allTemporarily disable JSON output functionality for forum posts
Restrict Access to JSON Endpoints
allUse web server configuration to restrict access to JSON API endpoints
# Apache: Add to .htaccess
RewriteCond %{QUERY_STRING} output=json [NC]
RewriteRule .* - [F,L]
# Nginx: Add to server block
location ~* \.php$ {
if ($args ~* "output=json") {
return 403;
}
}
🧯 If You Can't Patch
- Implement strict network access controls to limit who can access the forum system
- Audit and remove sensitive information from custom fields until patching is possible
🔍 How to Verify
Check if Vulnerable:
Test if custom field data is accessible via JSON output when it shouldn't be based on ACL settings. Create a post with custom fields, set restrictive permissions, then attempt to access via JSON endpoint.Check Version:
Check EasyDiscuss version in administration panel or review component files for version informationVerify Fix Applied:
After patching, repeat the vulnerability test to confirm custom field data is no longer accessible via JSON when permissions should restrict it.📡 Detection & Monitoring
Log Indicators:
- Unusual access patterns to JSON endpoints
- Requests with output=json parameter accessing restricted content
- Increased traffic to custom field-related endpoints
Network Indicators:
- HTTP requests containing 'output=json' parameter
- Unusual data extraction patterns from forum APIs
SIEM Query:
web.url:*output=json* AND (web.status:200 OR web.status:403) AND NOT user.role:admin