CVE-2026-27918

Windows Shell Elevation of Privilege Vulnerability

At a glance

Severity: HIGH 7.8
EPSS: EPSS 0.19 % · percentile 9 (2026-10-27)
State: PUBLISHED
Published: 2026-04-14
Updated: 2026-10-15
Assigner: microsoft
NVD status: Analyzed

Description

Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Shell allows an authorized attacker to elevate privileges locally.

Scores

Version	Score	Vector	Scored by
CVSS 3.1	HIGH 7.8	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C	microsoft
CVSS 3.1	HIGH 7.8	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H	NVD · secure@microsoft.com (Secondary)
CVSS 3.1	HIGH 7.0	CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H	NVD · nvd@nist.gov (Primary)

Weaknesses (CWE)

CWE-362

European references

ENISA EUVD · EUVD-2026-22462
GCVE · GCVE-0-2026-27918

CERT-FR advisories

CERTFR-2026-AVI-0442 — Multiples vulnérabilités dans Microsoft Windows · cert.ssi.gouv.fr

Affected configurations (NVD CPE)

cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x64:* < 10.0.17763.8644
cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x86:* < 10.0.17763.8644
cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:arm64:* < 10.0.19044.7184
cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:x64:* < 10.0.19044.7184
cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:x86:* < 10.0.19044.7184
cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:arm64:* < 10.0.19045.7184
cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:x64:* < 10.0.19045.7184
cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:x86:* < 10.0.19045.7184
cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:arm64:* < 10.0.22631.6936
cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:x64:* < 10.0.22631.6936
cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:arm64:* < 10.0.26100.8246
cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:x64:* < 10.0.26100.8246
cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:arm64:* < 10.0.26200.8246
cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:x64:* < 10.0.26200.8246
cpe:2.3:o:microsoft:windows_11_26h1:*:*:*:*:*:*:arm64:* < 10.0.28000.1836
cpe:2.3:o:microsoft:windows_11_26h1:*:*:*:*:*:*:x64:* < 10.0.28000.1836
cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:* < 10.0.17763.8644
cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:* < 10.0.20348.5020
cpe:2.3:o:microsoft:windows_server_2022_23h2:*:*:*:*:*:*:*:* < 10.0.25398.2274
cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:* < 10.0.26100.32690

Affected products

Product	Versions
Microsoft · Windows 10 Version 1809	affected 10.0.17763.0 < 10.0.17763.8644
Microsoft · Windows 10 Version 21H2	affected 10.0.19044.0 < 10.0.19044.7184
Microsoft · Windows 10 Version 22H2	affected 10.0.19045.0 < 10.0.19045.7184
Microsoft · Windows 11 version 23H2	affected 10.0.22631.0 < 10.0.22631.6936
Microsoft · Windows 11 Version 23H2	affected 10.0.22631.0 < 10.0.22631.6936
Microsoft · Windows 11 Version 24H2	affected 10.0.26100.0 < 10.0.26100.8246
Microsoft · Windows 11 Version 25H2	affected 10.0.26200.0 < 10.0.26200.8246
Microsoft · Windows 11 version 26H1	affected 10.0.28000.0 < 10.0.28000.1836
Microsoft · Windows Server 2019	affected 10.0.17763.0 < 10.0.17763.8644
Microsoft · Windows Server 2019 (Server Core installation)	affected 10.0.17763.0 < 10.0.17763.8644
Microsoft · Windows Server 2022	affected 10.0.20348.0 < 10.0.20348.5020
Microsoft · Windows Server 2022, 23H2 Edition (Server Core installation)	affected 10.0.25398.0 < 10.0.25398.2274
Microsoft · Windows Server 2025	affected 10.0.26100.0 < 10.0.26100.32690
Microsoft · Windows Server 2025 (Server Core installation)	affected 10.0.26100.0 < 10.0.26100.32690

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-27918

Sources

Source	Licence
CVE List (CVEProject cvelistV5)	CVE Program Terms of Use
EPSS (FIRST.org)	FIRST — attribution requested
ENISA EUVD	ENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)	Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feeds	Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD