CVE-2025-54478
📋 TL;DR
The Mattermost Confluence Plugin before version 1.5.0 has an authentication bypass vulnerability that allows unauthenticated attackers to edit channel subscriptions via API calls. This affects organizations using the vulnerable plugin to integrate Mattermost with Confluence. Attackers can manipulate notification settings without valid credentials.
💻 Affected Systems
- Mattermost Confluence Plugin
📦 What is this software?
Confluence by Mattermost
⚠️ Risk & Real-World Impact
Worst Case
Attackers could redirect sensitive notifications to unauthorized channels, modify critical communication flows, or disrupt team collaboration by altering subscription settings across the organization.
Likely Case
Attackers would typically modify channel subscriptions to redirect notifications, potentially exposing sensitive information or disrupting workflow communications.
If Mitigated
With proper network segmentation and access controls, impact would be limited to unauthorized subscription changes within the Mattermost instance.
🎯 Exploit Status
Direct API call to vulnerable endpoint without authentication required.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.5.0
Vendor Advisory: https://mattermost.com/security-updates
Restart Required: Yes
Instructions:
1. Access Mattermost System Console 2. Navigate to Plugins 3. Update Confluence Plugin to version 1.5.0 4. Restart Mattermost server
🔧 Temporary Workarounds
Disable Confluence Plugin
allTemporarily disable the vulnerable plugin until patching is possible
mmctl plugin disable com.mattermost.confluence
Restrict API Access
allUse network controls to restrict access to Mattermost API endpoints
🧯 If You Can't Patch
- Disable the Confluence plugin entirely
- Implement strict network ACLs to restrict access to Mattermost API endpoints from untrusted networks
🔍 How to Verify
Check if Vulnerable:
Check plugin version in Mattermost System Console > Plugins > Confluence PluginCheck Version:
mmctl plugin list | grep confluenceVerify Fix Applied:
Verify plugin version shows 1.5.0 or higher in System Console📡 Detection & Monitoring
Log Indicators:
- Unauthenticated POST requests to /plugins/com.mattermost.confluence/api/v1/channel-subscriptions
- Failed authentication attempts followed by successful subscription modifications
Network Indicators:
- Unusual API calls to Confluence plugin endpoints from external IPs
- Traffic to Mattermost API without authentication headers
SIEM Query:
source="mattermost" AND (uri_path="/plugins/com.mattermost.confluence/api/v1/channel-subscriptions" AND http_method="POST") AND NOT (user_id EXISTS)