CVE-2026-63117
Received Received - Intake

Remote Code Execution in FreeRDP

Publication date: 2026-08-19

Last updated on: 2026-08-19

Assigner: GitHub, Inc.

Description
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.28.0, an authenticated RDP client can advertise DVI ADPCM with nBlockAlign equal to 8 and nChannels equal to 2 to make the `bs` calculation in rdpsnd_server_select_format in channels/rdpsnd/server/rdpsnd_main.c equal zero. The subsequent out_frames modulo `bs` operation raises SIGFPE and terminates the server-side rdpsnd channel process. This vulnerability fixed in 3.28.0.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published
2026-08-19
Last Modified
2026-08-19
Generated
2026-08-19
AI Q&A
2026-08-19
EPSS Evaluated
N/A
NVD
CVE-2026-63117
EUVD
EUVD-2026-62670

Affected Vendors & Products

Showing 2 associated CPEs
Vendor Product Version / Range
freerdp freerdp to 3.28.0 (inc)
freetdp freetdp 3.28.0

Helpful Resources

Exploitability

CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-369 The product divides a value by zero.

Attack-Flow Graph

AI Quick Actions

Instant insights powered by AI
Executive Summary

This vulnerability in FreeRDP is a denial of service (DoS) flaw caused by improper ADPCM frame size calculation. An authenticated RDP client can send specific values for nBlockAlign and nChannels that make the frame size calculation result in zero. This triggers a division by zero error, causing a SIGFPE signal and crashing the server-side rdpsnd channel process.

Detection Guidance

Detecting this vulnerability requires monitoring for crashes in the FreeRDP rdpsnd channel process. Check FreeRDP server logs for SIGFPE errors or unexpected terminations in the sound channel. Use network monitoring tools to detect malformed ADPCM audio format advertisements from clients.

Impact Analysis

The primary impact is a denial of service on the FreeRDP server. The server-side rdpsnd channel crashes, disrupting sound functionality for all connected clients. The attack requires low privileges and no user interaction, making it relatively easy to exploit.

Compliance Impact

This vulnerability causes a denial of service (DoS) by crashing the server-side rdpsnd channel through a SIGFPE signal, which could disrupt remote desktop services. While it does not directly impact data confidentiality or integrity, prolonged service disruption may affect compliance with availability requirements in standards like GDPR (Article 32) or HIPAA (Security Rule). Organizations relying on FreeRDP for remote access must ensure timely patching to maintain service availability and regulatory compliance.

Mitigation Strategies

Upgrade FreeRDP to version 3.28.0 or later immediately. If upgrading is not possible, restrict RDP access to trusted clients only and monitor for suspicious audio format advertisements in network traffic.

Chat Assistant

Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-63117. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70

EPSS Chart