Critical Vulnerability in FreeRDP: Protocol Negotiation Bypass
Summary
ALSA-2026:73979: Critical: freerdp security update. Affects freerdp versions < 2:3.10.3-12.el10_2.13. Fixed in 2:3.10.3-12.el10_2.13. How to fix ↓
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Background
FreeRDP is a free implementation of the Remote Desktop Protocol (RDP) that allows users to connect to RDP servers, such as Microsoft Windows machines, xrdp, and VirtualBox. Released under the Apache license, FreeRDP is widely used for remote desktop access in various environments. The recent vulnerability affects versions 3.0.0 through 3.30.0, allowing attackers to bypass protocol negotiation, potentially leading to unauthorized access.
Vulnerability Detail
The vulnerability, identified as CVE-2026-91949, is a Protocol Negotiation Bypass in FreeRDP. This flaw allows an attacker to exploit the protocol negotiation process, which could lead to unauthorized access to sensitive systems. The issue arises from improper handling of protocol negotiation, making it possible for attackers to connect to RDP servers without proper authentication. This vulnerability poses a significant risk, especially in environments where FreeRDP is used for remote access to critical systems.
How To Fix
Minimum fixed version
2:3.10.3-12.el10_2.13
This is the first release that contains the fix.
sudo dnf update freerdpTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary workaround, users can limit access to the RDP server by implementing firewall rules that restrict connections to trusted IP addresses only. This can help mitigate the risk until the package is updated.
Conclusion
The Protocol Negotiation Bypass vulnerability in FreeRDP poses a critical risk to systems using affected versions. Users are strongly advised to update to the patched version to mitigate potential threats. Implementing temporary workarounds can provide additional security until the update is completed.
See every vulnerability recorded for freerdp →
FAQ
FreeRDP is an open-source implementation of the Remote Desktop Protocol (RDP) that allows users to connect to remote desktop servers.
This vulnerability allows attackers to bypass the protocol negotiation process, potentially gaining unauthorized access to systems.
You can use Vulert's playground at Vulert Scanner to check if your application is affected by this vulnerability without any signup.
If immediate updates are not possible, implement firewall rules to restrict access to the RDP server as a temporary measure.
More details can be found on the CVE page for CVE-2026-91949, which provides comprehensive information about the vulnerability and its implications.
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