CVE-2026-66804

highpriority · track · 10EPSS 0.003 · 22 %ileexploit · PoCDEEUNLRUUS

grimoire priorityP1 · Urgent

Exploitable?

Public exploit

4 exploits · PoC

Likely / severe?

0.30% (22nd) EPSS

CVSS 7.8 · high

Is it mine?

85 products

Check your exposure

Who says so?

7 sources

cnnvd · enisa_euvd · fstec_bdu · cert_bund

EPSS · scored 2026-10-26

Improper access control in Windows Cross Device Service allows an authorized attacker to elevate privileges locally.

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

FixedWindows 10 Version 22H2 for 32-bit Systemsmsrc_csaf
10.0.19045.7663:Security Update:https://support.microsoft.com/help/5120249
https://support.microsoft.com/help/5120249
FixedWindows 10 Version 22H2 for ARM64-based Systemsmsrc_csaf
10.0.19045.7663:Security Update:https://support.microsoft.com/help/5120249
https://support.microsoft.com/help/5120249
FixedWindows 10 Version 22H2 for x64-based Systemsmsrc_csaf
10.0.19045.7663:Security Update:https://support.microsoft.com/help/5120249
https://support.microsoft.com/help/5120249
FixedWindows 11 Version 24H2 for ARM64-based Systemsmsrc_csaf
10.0.26100.9106:Security Hotpatch Update:https://support.microsoft.com/help/5120994
https://support.microsoft.com/help/5120994
FixedWindows 11 Version 24H2 for x64-based Systemsmsrc_csaf
10.0.26100.9106:Security Hotpatch Update:https://support.microsoft.com/help/5120994
https://support.microsoft.com/help/5120994
FixedWindows 11 Version 25H2 for ARM64-based Systemsmsrc_csaf
10.0.26200.9106:Security Hotpatch Update:https://support.microsoft.com/help/5120994
https://support.microsoft.com/help/5120994
FixedWindows 11 Version 25H2 for x64-based Systemsmsrc_csaf
10.0.26200.9106:Security Hotpatch Update:https://support.microsoft.com/help/5120994
https://support.microsoft.com/help/5120994
FixedWindows 11 Version 26H1 for ARM64-based Systemsmsrc_csaf
10.0.28000.2704:Security Update:https://support.microsoft.com/help/5121000
https://support.microsoft.com/help/5121000
FixedWindows 11 version 26H1 for x64-based Systemsmsrc_csaf
10.0.28000.2704:Security Update:https://support.microsoft.com/help/5121000
https://support.microsoft.com/help/5121000

cvss

Technical severity, 0–10. One row per scoring source.

7.8

010

base score 0–10 · higher = more severe · hover a vector to decode

v3.17.8highAV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU

v3.17.8highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:Csecondary · ENISA EU

v3.17.8highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsecondary · secure@microsoft.com USexploitability 1.8 · impact 5.9

v3.17.4highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:Psecondary · CVSS-BT (t0sche)

v3.17.8highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:Csecondary · NCSC-NL NL

v3.17.8highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:Csecondary · Microsoft Security Response Center US

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: no · Technical Impact: totalcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-284USCWE-284USCWE-284US

exploits (4)

Public proof-of-concept and weaponised exploit code.

CypherHippie/CVE-2026-66804CypherHippie/CVE-2026-66804PoC · poc_in_github
DavidCarliez/CVE-2026-66804-CrossDevice-LPEDavidCarliez/CVE-2026-66804-CrossDevice-LPEPoC · poc_in_github
Rat5ak/CVE-2026-66804-CrossDevice-Service-EoPCVE-2026-66804 Windows Cross Device virtual camera EoP - Standard user to SYSTEMPoC · poc_in_github
ZeroDayVPN/CVE-2026-66804-CrossDevice-Service-EoPsadsadsaPoC · poc_in_github

affected products (85)

Products and version ranges known to be affected.

Dell Computerall versionscert_bundDEcpe:/o:dell:dell_computer:-
Dell PowerEdge serverall versionscert_bundDEcpe:/h:dell:poweredge:server
Dell PowerScale OneFSall versionscert_bundDEcpe:/a:dell:powerscale_onefs:-
Hitachi Storageall versionscert_bundDEcpe:/h:hitachi:storage:-
Lenovo Computerall versionscert_bundDEcpe:/h:lenovo:computer:-
Microsoft Exchange Server 2016 Cumulative Update 23all versionscert_bundDEcpe:/a:microsoft:exchange:server_2016_cumulative_update_23
Microsoft Exchange Server 2019 Cumulative Update 14all versionscert_bundDEcpe:/a:microsoft:exchange:server_2019_cumulative_update_14
Microsoft Exchange Server 2019 Cumulative Update 15all versionscert_bundDEcpe:/a:microsoft:exchange:server_2019_cumulative_update_15
Microsoft Windows 10 Version 1607all versionscert_bundDEcpe:/o:microsoft:windows_10:version_1607
Microsoft Windows 10 Version 1809all versionscert_bundDEcpe:/o:microsoft:windows_10:version_1809
Microsoft Windows 10 Version 21H2all versionscert_bundDEcpe:/o:microsoft:windows_10:version_21h2
Microsoft Windows 10 Version 22H2all versionscert_bundDEcpe:/o:microsoft:windows_10:version_22h2
Microsoft Windows 11 Version 23H2all versionscert_bundDEcpe:/o:microsoft:windows_11:version_23h2
Microsoft Windows 11 Version 24H2all versionscert_bundDEcpe:/o:microsoft:windows_11:version_24h2
Microsoft Windows 11 Version 25H2all versionscert_bundDEcpe:/o:microsoft:windows_11:version_25h2
Microsoft Windows 11 Version 26H1all versionscert_bundDEcpe:/o:microsoft:windows_11:version_26h1
Microsoft Windows App Client for Desktopall versionscert_bundDEcpe:/o:microsoft:windows:app_client_for_desktop
Microsoft Windows Server 2012all versionscert_bundDEcpe:/o:microsoft:windows_server_2012:-
Microsoft Windows Server 2012 R2all versionscert_bundDEcpe:/o:microsoft:windows_server_2012_r2:-
Microsoft Windows Server 2016all versionscert_bundDEcpe:/o:microsoft:windows_server_2016:-

showing 20 of 85

advisories (4)

Vendor and ecosystem advisories describing this.

NCSC-2026-0284Kwetsbaarheden verholpen in Microsoft WindowsNL2026-08-11csaf · ncsc_nlNL
Microsoft heeft een groot aantal kwetsbaarheden verholpen in Windows.
WID-SEC-W-2026-2756Microsoft Windows Produkte: Mehrere SchwachstellenDeutsch2026-08-11csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in Microsoft Windows Server 2012, Microsoft Windows Server 2012 R2, Microsoft Windows Server 2016, Microsoft Windows 10, Microsoft Windows Server 2019, Microsoft Windows Server 2022, Microsoft Exchange, Microsoft Windows 11, Microsoft Windows Server 2025 und Microsoft Windows ausnutzen, um beliebigen Programmcode auszuführen, um seine Privilegien zu erhöhen, um einen Denial of Service Angriff durchzuführen, um Informationen offenzulegen, um Dateien zu manipulieren, um einen Cross-Site Scripting Angriff durchzuführen, und um Sicherheitsvorkehrungen zu umgehen.
msrc_CVE-2026-66804Microsoft Windows Cross Device Service Elevation of Privilege Vulnerability2026-08-11csaf · msrc_csafUS
To determine the support lifecycle for your software, see the Microsoft Support Lifecycle: https://support.microsoft.com/lifecycle
ZDI-26-617ZDI advisory ZDI-26-6172026-09-08vendor · zdiUS

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu cert_bund ncsc_nl msrc_csaf zdi NVD CVE.org MITRE

published 2026-08-11modified 2026-10-14

references (3)

External citations — patches, advisories, analysis.

scry

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