CVE-2026-27951
📋 TL;DR
This vulnerability in FreeRDP's Stream_EnsureCapacity function can cause an endless blocking loop, potentially leading to denial of service. It affects all FreeRDP client and server implementations on 32-bit systems with sufficient physical memory. The issue was patched in version 3.23.0.
💻 Affected Systems
- FreeRDP
📦 What is this software?
Freerdp by Freerdp
⚠️ Risk & Real-World Impact
Worst Case
Complete denial of service on affected FreeRDP instances, making RDP services unavailable until restart.
Likely Case
Service disruption or instability on vulnerable 32-bit systems when specific memory conditions are met.
If Mitigated
Minimal impact if patched or running on 64-bit systems or systems with insufficient memory.
🎯 Exploit Status
Exploitation requires specific memory conditions and targeting of FreeRDP instances. No public exploit code is known.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 3.23.0
Vendor Advisory: https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-qcfc-ghxr-h927
Restart Required: Yes
Instructions:
1. Download FreeRDP version 3.23.0 or later from official sources. 2. Stop all FreeRDP services. 3. Install the updated version. 4. Restart FreeRDP services.
🧯 If You Can't Patch
- Migrate to 64-bit systems where the vulnerability does not apply.
- Limit FreeRDP usage to trusted networks only.
🔍 How to Verify
Check if Vulnerable:
Check FreeRDP version with 'xfreerdp --version' or equivalent command for your platform. If version is below 3.23.0 and running on 32-bit system, it is vulnerable.Check Version:
xfreerdp --versionVerify Fix Applied:
Confirm FreeRDP version is 3.23.0 or higher using 'xfreerdp --version' and verify system is 64-bit or has insufficient memory for exploitation.📡 Detection & Monitoring
Log Indicators:
- Unusual FreeRDP process hangs or crashes
- High memory usage patterns in FreeRDP processes
Network Indicators:
- RDP connection failures to FreeRDP services
- Unresponsive FreeRDP endpoints
SIEM Query:
Process:FreeRDP AND (EventID:1000 OR EventID:1001) OR MemoryUsage:>90%