---
id: "CVE-2026-121958"
kind: "vulnerability"
aliases: ["CVE-2026-121958"]
title: "FreeRDP: malicious RDP server can overwrite client memory via graphics channel"
severity: "high"
cvss: 8.8
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["c", "freerdp", "package", "rdp", "remote-desktop"]
not_affected_if: ["no-freerdp-clients", "trusted-servers-only"]
published_at: "2026-11-04T16:17:48+00:00"
first_seen_at: "2026-11-04T16:28:14+00:00"
updated_at: "2026-11-04T16:28:33+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-121958", "first_seen_at": "2026-11-04T16:28:14+00:00"}]
---

# FreeRDP: malicious RDP server can overwrite client memory via graphics channel

FreeRDP through 3.32.1 has a heap out-of-bounds write in its RDPGFX graphics client, caused by a surface-key truncation bug in the delete_surface callback. A malicious or man-in-the-middle RDP server can trigger it with crafted surface delete and frame messages, corrupting client memory.

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

## How to check

- Check the FreeRDP version installed on the client, for example with `xfreerdp --version`, and compare it to the fixed release in the vendor advisory.
- Find out whether applications or tools that embed FreeRDP are installed and which version they bundle.

## Fix

- FreeRDP versions after `3.32.1` are the sources' stated range; the specific fixed version is unknown from the sources.

## Timeline

- 2026-11-04T16:28:14+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-121958

## Documents

- [advisory] Vendor advisory: github.com https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-m59q-wm7v-mp57
- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/freerdp-through-3.32.1-heap-out-of-bounds-write-via-rdpgfx-hashtable-getkeys

## From the sources

FreeRDP through 3.32.1 has a heap out-of-bounds write in the RDPGFX client because the delete_surface callback truncates surface hash keys to 16 bits, leaving the surface table inconsistent so HashTable_GetKeys writes past its allocated key array. A malicious or man-in-the-middle RDP server can exploit this by creating surfaceId 0xFFFF, closing the RDPGFX channel, sending repeated DELETESURFACE PDUs, and then sending ENDFRAME or RESETGRAPHICS.

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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_