---
id: "CVE-2026-121407"
kind: "vulnerability"
aliases: ["CVE-2026-121407"]
title: "FreeRDP: crafted remdesk payload crashes the shadow server, dropping sessions"
severity: "high"
cvss: 7.1
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["freerdp", "linux", "rdp", "runtime", "shadow-server", "windows"]
not_affected_if: ["client-only", "managed-hosting", "no-shadow-server"]
published_at: "2026-11-03T15:17:29+00:00"
first_seen_at: "2026-11-03T15:21:58+00:00"
updated_at: "2026-11-03T15:22:58+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-121407", "first_seen_at": "2026-11-03T15:21:58+00:00"}]
---

# FreeRDP: crafted remdesk payload crashes the shadow server, dropping sessions

FreeRDP's shadow server has an inverted PDU length check in its remdesk thread, so a crafted payload makes the process abort on a Stream_Seek assertion. An authenticated client can take the server down and drop active sessions.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the FreeRDP version with `xfreerdp --version` or the package manager, and see whether it is below `3.32.2`
- Confirm whether the shadow server (`freerdp-shadow`) is running and accepting connections

## Fix

- FreeRDP: move to `3.32.2` or later

## Timeline

- 2026-11-03T15:21:58+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-121407

## Documents

- [advisory] Vendor advisory: github.com https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-x8vp-ff7m-294g
- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/freerdp-before-3.32.2-shadow-server-denial-of-service-via-remdesk-channel

## From the sources

FreeRDP before 3.32.2 contains a denial of service vulnerability in the shadow server's remdesk_server_thread that allows authenticated clients to crash the process via an inverted PDU length check. Attackers can send an 8192-byte remdesk payload declaring an eight-byte PDU length to trigger a fatal Stream_Seek assertion, aborting the server and dropping sessions.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_