CVE-2025-68479
📋 TL;DR
This CVE describes an authorization bypass vulnerability in Discourse discussion platform where subscription endpoints lack proper ownership verification before allowing modifications. Attackers could manipulate other users' subscriptions without permission. All Discourse instances running vulnerable versions are affected.
💻 Affected Systems
- Discourse
📦 What is this software?
Discourse by Discourse
Discourse by Discourse
Discourse by Discourse
Discourse by Discourse
⚠️ Risk & Real-World Impact
Worst Case
Attackers could modify any user's subscription settings, potentially causing denial of service, privacy violations, or enabling further attacks through subscription manipulation.
Likely Case
Unauthorized users modifying other users' subscription preferences, leading to notification spam, missed important updates, or minor privacy violations.
If Mitigated
With proper network segmentation and access controls, impact would be limited to authenticated users within the same security zone.
🎯 Exploit Status
Exploitation requires authenticated access but minimal technical skill to manipulate API calls.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 3.5.4, 2025.11.2, 2025.12.1, or 2026.1.0
Vendor Advisory: https://github.com/discourse/discourse/security/advisories/GHSA-6gjr-5897-m327
Restart Required: Yes
Instructions:
1. Backup your Discourse instance. 2. Update to one of the patched versions using your deployment method (Docker, manual, etc.). 3. Restart the Discourse service. 4. Verify the update was successful.
🧯 If You Can't Patch
- Implement strict network access controls to limit Discourse API access to trusted users only.
- Monitor subscription-related API calls for unauthorized modifications and implement rate limiting.
🔍 How to Verify
Check if Vulnerable:
Check Discourse version via admin panel or run: docker exec -it discourse cat /usr/src/discourse/VERSIONCheck Version:
docker exec -it discourse cat /usr/src/discourse/VERSIONVerify Fix Applied:
Confirm version is 3.5.4, 2025.11.2, 2025.12.1, or 2026.1.0 or higher📡 Detection & Monitoring
Log Indicators:
- Unusual subscription modification patterns
- API calls to subscription endpoints from unexpected users
Network Indicators:
- Unusual volume of POST/PUT requests to /subscription endpoints
SIEM Query:
source="discourse" AND (uri_path="/subscription" OR uri_path="/subscriptions") AND http_method IN ("POST", "PUT", "DELETE")