---
id: "CVE-2026-121394"
kind: "vulnerability"
aliases: ["CVE-2026-121394"]
title: "FreeRDP: malicious RDP server crashes clients via RemoteFX decoder assertion"
severity: "high"
cvss: 7.1
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["freerdp", "linux", "remote-desktop", "runtime", "windows"]
not_affected_if: ["older-or-newer-version", "trusted-servers-only"]
published_at: "2026-11-03T15:17:27+00:00"
first_seen_at: "2026-11-03T15:21:57+00:00"
updated_at: "2026-11-03T15:23:05+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-121394", "first_seen_at": "2026-11-03T15:21:57+00:00"}]
---

# FreeRDP: malicious RDP server crashes clients via RemoteFX decoder assertion

FreeRDP from 3.11.0 before 3.32.2 has an assertion failure in its RemoteFX RLGR decoder. A malicious RDP server can send a crafted RemoteFX tileset that makes the client crash.

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

## How to check

- Check the installed FreeRDP version with `xfreerdp --version` or the package manager, and compare against the fixed range.
- Confirm whether the client connects to servers you do not control.

## Fix

- FreeRDP `3.32.2` and later, per the NVD description (affected range 3.11.0 before 3.32.2).

## Timeline

- 2026-11-03T15:21:57+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-121394

## Documents

- [advisory] Vendor advisory: github.com https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-5j39-x36c-x9pm
- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/freerdp-before-3.32.2-denial-of-service-via-remotefx-rlgr-decoder

## From the sources

FreeRDP from 3.11.0 before 3.32.2 contains an assertion failure in the RemoteFX RLGR decoder that allows malicious servers to terminate clients. Attackers controlling an RDP server can send a RemoteFX tileset with RLGR code 32767, triggering a signed narrowing assertion in rfx_rlgr_decode and crashing the client.

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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_