FreeRDP: Denial of Service in WinPR via malformed clipboard images (CVE-2026-121386)

FreeRDP versions before 3.32.2 contain a denial of service vulnerability located in the WinPR library's winpr_read_png_from_buffer() and winpr_convert_from_jpeg() functions. The vulnerability stems from insufficient error handling when interacting with the libpng and libjpeg libraries. An attacker acting as a malicious RDP server or performing a man-in-the-middle (MITM) attack can trigger this flaw by providing a malformed PNG or a truncated JPEG payload via the RDP clipboard channel. Successful exploitation causes the FreeRDP client process to abort or terminate unexpectedly.

Impact

The vulnerability allows an unauthenticated remote attacker to cause a denial of service by crashing the client application. No code execution is documented as part of this vulnerability.

Recommendation

Update all instances of the FreeRDP client to version 3.32.2 or later immediately to incorporate the required error handling for image processing functions.