CVE-2026-110838: FreeRDP shadow before 3.32.0 Pre-Authentication Input Injection via Confirm Active bypass
FreeRDP shadow server from 3.0.0 before 3.32.0 dispatches input PDUs during the Confirm Active state before authentication, allowing unauthenticated attackers to inject keyboard input. Attackers can negotiate TLS-only RDP and send an input PDU without Confirm Active to inject synthetic keystrokes into the host user's X11 session via XTEST.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
FreeRDP shadow serverto a version that resolves this vulnerability.Fixed in 3.32.0
Event History
Frequently Asked Questions
Which deployments are exposed?
FreeRDP shadow server deployments running versions from 3.0.0 before 3.32.0 are affected. The issue involves injection into the host user's X11 session via XTEST.
What does an attacker need to exploit this?
An attacker needs network access to the shadow server and can use a TLS-only RDP negotiation. No authentication or user interaction is required; the attacker sends an input PDU without completing Confirm Active.
What is the impact of successful exploitation?
A successful attacker can inject synthetic keyboard input into the host user's X11 session. The reported impact is integrity loss, with no stated confidentiality or availability impact.