Bug 2565951 (CVE-2026-121404)

Summary: CVE-2026-121404 freerdp: freerdp: Denial of Service via zero-length dynamic virtual channel messages
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in FreeRDP. An authenticated remote attacker can cause a Denial of Service (DoS) by sending zero-length dynamic virtual channel data messages to the shadow server over an established Remote Desktop Protocol (RDP) session. Because the server fails to properly consume these empty messages, receiving server threads enter an infinite loop. This behavior exhausts system CPU resources and degrades performance until the client disconnects.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-11-03 16:46:46 UTC
FreeRDP before 3.32.2 contains a denial of service vulnerability in the shadow server that allows authenticated RDP clients to spin server threads by sending zero-length drdynvc DATA PDUs. Attackers can send empty DATA messages on opened audin or rdpgfx channels, so that FreeRDP_WTSVirtualChannelRead never consumes them, consuming full CPU cores until disconnect.