---
id: "CVE-2026-121956"
kind: "vulnerability"
aliases: ["CVE-2026-121956"]
title: "FreeRDP: double free in Kerberos SSPI lets unauthenticated clients crash server"
severity: "high"
cvss: 8.7
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["freerdp", "kerberos", "package", "rdp-server", "winpr"]
not_affected_if: ["fixed-version", "no-rdp-server"]
published_at: "2026-11-04T16:17:48+00:00"
first_seen_at: "2026-11-04T16:28:11+00:00"
updated_at: "2026-11-04T16:28:42+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-121956", "first_seen_at": "2026-11-04T16:28:11+00:00"}]
---

# FreeRDP: double free in Kerberos SSPI lets unauthenticated clients crash server

FreeRDP before 3.32.2 has a double free in the WinPR Kerberos SSPI code path that handles a crafted NLA/CredSSP u2u TGT request. An unauthenticated remote client can corrupt the heap and crash the server process.

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

## How to check

- Check the FreeRDP version the server runs, for example with `xfreerdp --version` or your package manager's query, and compare it to `3.32.2`.
- Confirm whether the server accepts NLA/CredSSP connections, which the sources describe as the reachable path.

## Fix

- FreeRDP: move to `3.32.2` or later.

## Timeline

- 2026-11-04T16:28:11+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-121956

## Documents

- [advisory] Vendor advisory: github.com https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-2557-79qc-6gfr
- [advisory] Third-party advisory: www.vulncheck.com https://www.vulncheck.com/advisories/freerdp-before-3.32.2-double-free-in-winpr-kerberos-retrievesometgt

## From the sources

FreeRDP before 3.32.2 contains a double free in the WinPR Kerberos SSPI retrieveSomeTgt function, which installs the krb5 default realm into a target principal that has an empty realm without taking ownership of it. Unauthenticated remote clients can send a crafted NLA/CredSSP u2u TGT request whose server-name component contains '@' to corrupt the heap and crash the server 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_