CVE-2026-21240

Windows HTTP.sys Elevation of Privilege Vulnerability

En bref

Time-of-check time-of-use (toctou) race condition in Windows HTTP.sys allows an authorized attacker to elevate privileges locally.

Version	Score	Vecteur	Évalué par
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)

CERTFR-2026-AVI-0150 — Multiples vulnérabilités dans Microsoft Windows · cert.ssi.gouv.fr

cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x64:* < 10.0.17763.8389
cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x86:* < 10.0.17763.8389
cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:arm64:* < 10.0.19044.6937
cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:x64:* < 10.0.19044.6937
cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:x86:* < 10.0.19044.6937
cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:arm64:* < 10.0.19045.6937
cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:x64:* < 10.0.19045.6937
cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:x86:* < 10.0.19045.6937
cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:arm64:* < 10.0.22631.6649
cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:x64:* < 10.0.22631.6649
cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:arm64:* < 10.0.26100.7781
cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:x64:* < 10.0.26100.7781
cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:arm64:* < 10.0.26200.7781
cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:x64:* < 10.0.26200.7781
cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:* < 10.0.17763.8389
cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:* < 10.0.20348.4711
cpe:2.3:o:microsoft:windows_server_2022_23h2:*:*:*:*:*:*:*:* < 10.0.25398.2149
cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:* < 10.0.26100.32313

Produit	Versions
Microsoft · Windows 10 Version 1809	affected 10.0.17763.0 < 10.0.17763.8389
Microsoft · Windows 10 Version 21H2	affected 10.0.19044.0 < 10.0.19044.6937
Microsoft · Windows 10 Version 22H2	affected 10.0.19045.0 < 10.0.19045.6937
Microsoft · Windows 11 version 22H3	affected 10.0.22631.0 < 10.0.22631.6649
Microsoft · Windows 11 Version 23H2	affected 10.0.22631.0 < 10.0.22631.6649
Microsoft · Windows 11 Version 24H2	affected 10.0.26100.0 < 10.0.26100.7840
Microsoft · Windows 11 Version 25H2	affected 10.0.26200.0 < 10.0.26200.7840
Microsoft · Windows 11 version 26H1	affected 10.0.28000.0 < 10.0.28000.1575
Microsoft · Windows 11 Version 26H1	affected 10.0.28000.0 < 10.0.28000.1575
Microsoft · Windows Server 2019	affected 10.0.17763.0 < 10.0.17763.8389
Microsoft · Windows Server 2019 (Server Core installation)	affected 10.0.17763.0 < 10.0.17763.8389
Microsoft · Windows Server 2022	affected 10.0.20348.0 < 10.0.20348.4773
Microsoft · Windows Server 2022, 23H2 Edition (Server Core installation)	affected 10.0.25398.0 < 10.0.25398.2149
Microsoft · Windows Server 2025	affected 10.0.26100.0 < 10.0.26100.32370
Microsoft · Windows Server 2025 (Server Core installation)	affected 10.0.26100.0 < 10.0.26100.32370

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