Buffer Overflow Vulnerability in FreeRDP Remote Desktop Protocol Implementation

CVE-2026-55192

What is CVE-2026-55192?

FreeRDP's implementation of the Remote Desktop Protocol has a vulnerability in its H.264 decoder prior to version 3.27.0. The issue occurs when the H.264 decoder backends do not correctly validate the dimension of the surfaces in use against the dimensions defined in the bitstream. A malicious RDP server could exploit this flaw by providing a specially crafted AVC420 or AVC444 bitstream with a decoded frame that is smaller than the expected negotiated surface size. This could lead to reading beyond the allocated memory for the decoder, potentially disclosing sensitive client memory or causing the client application to crash. The vulnerability is resolved in version 3.27.0.

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