CVE-2026-121394
Undergoing Analysis Undergoing Analysis - In Progress

RemoteFX RLGR Decoder Assertion Failure in FreeRDP

Publication date: 2026-11-03

Last updated on: 2026-11-03

Assigner: VulnCheck

Description
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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Meta Information

Published
2026-11-03
Last Modified
2026-11-03
Generated
2026-11-03
AI Q&A
2026-11-03
EPSS Evaluated
N/A
NVD
CVE-2026-121394
EUVD
EUVD-2026-115926

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
FreeRDP FreeRDP 3.11.0

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Exploitability

CWE
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KEV
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CWE ID Description
CWE-617 The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary.

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Executive Summary

This vulnerability is a denial-of-service flaw in FreeRDP versions 3.11.0 to 3.32.1. It occurs when a malicious RDP server sends a RemoteFX tileset with RLGR code 32767, triggering an assertion failure in the RemoteFX RLGR decoder. This causes the client to crash without memory corruption or data loss.

Detection Guidance

To detect this vulnerability, check if your FreeRDP client version is between 3.11.0 and 3.32.1. Run 'xfreerdp --version' or 'freerdp2 --version' to verify the installed version. If RemoteFX decoding is enabled in client configurations, monitor for unexpected client crashes when connecting to untrusted RDP servers.

Impact Analysis

If you connect to a controlled RDP server with RemoteFX decoding enabled, the server can crash your FreeRDP client. This results in a denial of service, terminating your session without affecting confidentiality or integrity of data.

Compliance Impact

This vulnerability primarily impacts availability by causing client crashes. It does not lead to data breaches or integrity loss, so it likely has minimal direct impact on GDPR or HIPAA compliance unless service disruption violates availability requirements.

Mitigation Strategies
  • Upgrade FreeRDP to version 3.32.2 or later to patch the vulnerability.
  • Disable RemoteFX decoding in FreeRDP client configurations if not required.
  • Avoid connecting to untrusted RDP servers until the client is updated.

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