ReviewHigh

CVE-2026-63409

deskflow

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.

CVSS: 8.2
EPSS: -
CISA KEV: Not listed
Published: 2026.08.18

PRIORITY ASSESSMENT

Review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability-

Technical severityCVSS 8.2

Vulnerability overview

Affected product and versions

Product: deskflow
Affected versions: >= >= 1.17.0, < 1.26.0.296
Fixed versions: No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

1
Identify
Confirm that deskflow and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H
CWE: CWE-125