---
id: "CVE-2026-121396"
kind: "vulnerability"
aliases: ["CVE-2026-121396"]
title: "FreeRDP client: malformed RD Gateway packet aborts the connecting client process"
severity: "medium"
cvss: 5.3
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["freerdp", "package", "rd-gateway", "remote-desktop"]
not_affected_if: ["direct-rdp-only", "non-verbose-build", "other-rdp-client"]
published_at: "2026-11-03T15:17:27+00:00"
first_seen_at: "2026-11-03T15:21:57+00:00"
updated_at: "2026-11-03T15:24:33+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-121396", "first_seen_at": "2026-11-03T15:21:57+00:00"}]
---

# FreeRDP client: malformed RD Gateway packet aborts the connecting client process

FreeRDP clients from 3.0.0 before 3.32.2, built with verbose WinPR assertions, crash when a connected RD Gateway sends a crafted RPC-over-HTTP packet with inconsistent authentication padding. An attacker controlling the gateway can abort the client process, which is a denial of service rather than code execution.

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

## How to check

- Check the FreeRDP client version with `xfreerdp /version` or the installed package version, and look for anything below `3.32.2`.
- Check whether the build enables verbose WinPR assertions; the sources do not say how to detect this.

## Fix

- FreeRDP clients: move to `3.32.2` or later.

## Timeline

- 2026-11-03T15:21:57+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-121396

## Documents

- [advisory] Vendor advisory: github.com https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-6p3w-fv52-cf24
- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/freerdp-3.0.0-before-3.32.2-denial-of-service-via-rts-padding-assertion

## From the sources

FreeRDP clients from 3.0.0 before 3.32.2 built with verbose WinPR assertions contain a reachable assertion in rts_read_auth_verifier triggered by malformed RTS padding. Attackers controlling an RD Gateway can send a crafted RPC-over-HTTP RTS PDU with inconsistent authentication padding to abort the connecting client process.

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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_