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Fencer Vulns
high 8.2

CVE-2026-63409 json

Deskflow: Odd-length DSOP options vector causes out-of-bounds read in Deskflow client

published 2026-08-17 2 mo ago modified 2026-09-09 1 mo ago also EUVD-2026-60463

cvss
8.2
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 39%
public exploits
0
none known

Summary

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.

Patch / fix

  • deskflow Debian 14 1.26.0+dfsg-4

debian advisories DEBIAN-CVE-2026-63409

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-63409 updated cvss 7.5

Deskflow: Deskflow: Client crash due to out-of-bounds read

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
2 mo ago

Exploit prediction

0.45% chance of exploitation in the next 30 days, higher than 39% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/deskflow/deskflow/security/advisories/GHSA-gmvh-3c73-m5gg referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 8.2 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H

Affected products

  • deskflow deskflow

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.