Bug 2517640 (CVE-2026-63409)

Summary: CVE-2026-63409 Deskflow: Deskflow: Client crash due to out-of-bounds read
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
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Priority: high    
Version: unspecifiedKeywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in Deskflow, a keyboard and mouse sharing application. A malicious Deskflow server can send a specially crafted data packet containing an odd-length DSOP (Deskflow Server Options Protocol) vector to a connected client. This triggers an out-of-bounds read vulnerability in the client's `ServerProxy::setOptions()` function, leading to the client crashing. This issue results in a denial of service for the affected client.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 2521881, 2521882    
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Description OSIDB Bzimport 2026-08-17 21:11:33 UTC
Deskflow is a keyboard and mouse sharing app. From 1.17.0 until continuous build 1.26.0.296, a malicious Deskflow server can send an odd-length DSOP vector to ServerProxy::setOptions() in src/lib/client/ServerProxy.cpp, causing the missing value after the final option key to be read beyond the vector during the PacketStreamFilter::filterEvent to ServerProxy::handleData() to ServerProxy::parseHandshakeMessage() call chain and crash the connected client. This issue is fixed in continuous build 1.26.0.296.