CVE-2026-42904

Windows TCP/IP Elevation of Privilege Vulnerability

State: Published
Severity: 9.6 Critical
Published: Jun 9, 2026
Updated: Sep 24, 2026
Reserved: Apr 30, 2026

Description

Heap-based buffer overflow in Windows TCP/IP allows an unauthorized attacker to elevate privileges over an adjacent network.

Scores

CVSS	Score	Vector	Source
3.1	9.6 Critical	CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C	microsoft

Weaknesses

CWE-122 Heap-based Buffer Overflow

Affected Products

Product	Versions
Windows 10 Version 21H2Microsoft	10.0.19044.0 to before 10.0.19044.7417Affected
Windows 10 Version 22H2Microsoft	10.0.19045.0 to before 10.0.19045.7417Affected
Windows 11 version 23H2Microsoft	10.0.22631.0 to before 10.0.22631.7219Affected
Windows 11 Version 23H2Microsoft	10.0.22631.0 to before 10.0.22631.7219Affected
Windows 11 Version 24H2Microsoft	10.0.26100.0 to before 10.0.26100.8655Affected
Windows 11 Version 25H2Microsoft	10.0.26200.0 to before 10.0.26200.8655Affected
Windows 11 version 26H1Microsoft	10.0.28000.0 to before 10.0.28000.2269Affected
Windows Server 2022Microsoft	10.0.20348.0 to before 10.0.20348.5256Affected
Windows Server 2025Microsoft	10.0.26100.0 to before 10.0.26100.32995Affected
Windows Server 2025 (Server Core installation)Microsoft	10.0.26100.0 to before 10.0.26100.32995Affected

References

Windows TCP/IP Elevation of Privilege Vulnerabilityvendor-advisorypatch

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