CVE-2026-42980 — NT OS Kernel Elevation of Privilege Vulnerability

Executive Summary

Integer underflow (wrap or wraparound) in Windows NT OS Kernel allows an authorized attacker to elevate privileges locally.

Overview

7.8

CVSS HIGH

Important

MS Severity

Not Exploited

MS Exploit Status

More Likely

MS Exploit Likelihood

Category Elevation of Privilege

Weakness CWE-191: Integer Underflow (Wrap or Wraparound)

Released Jun 9 2026

Last Updated Jun 9 2026

Publicly Disclosed No

CISA KEV Not Listed

Known Exploits None Known

EPSS Score 0.06949 — 0.9343 percentile

NVD CVSS 7.8 HIGH — matches MSRC

CVSS Vector

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

ATTACK VECTOR

Local

ATTACK COMPLEXITY

Low

PRIVILEGES REQUIRED

Low

USER INTERACTION

None

SCOPE

Unchanged

CONFIDENTIALITY

High

INTEGRITY

High

AVAILABILITY

High

EXPLOIT CODE MATURITY

Unproven

REMEDIATION LEVEL

Official Fix

REPORT CONFIDENCE

Confirmed

Temporal Score: 6.8

EPSS Score

0.06949

probability of exploitation in the next 30 days

0.9343 percentile - updated 2026-07-25

View on FIRST.org

Affected Products

30 affected products

Product	KB Article	Severity	Impact	Restart Required
Windows 10 Version 1607 for 32-bit Systems	`5094122 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1607 for x64-based Systems	`5094122 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1809 for 32-bit Systems	`5094123 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1809 for x64-based Systems	`5094123 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 21H2 for 32-bit Systems	`5094127 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 21H2 for ARM64-based Systems	`5094127 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 21H2 for x64-based Systems	`5094127 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 22H2 for 32-bit Systems	`5094127 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 22H2 for ARM64-based Systems	`5094127 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 22H2 for x64-based Systems	`5094127 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 11 Version 23H2 for ARM64-based Systems	`5093998 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 11 Version 23H2 for x64-based Systems	`5093998 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 11 Version 24H2 for ARM64-based Systems	`5094126 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 11 Version 24H2 for x64-based Systems	`5094126 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 11 Version 25H2 for ARM64-based Systems	`5094126 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 11 Version 25H2 for x64-based Systems	`5094126 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 11 Version 26H1 for ARM64-based Systems	`5095051 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 11 version 26H1 for x64-based Systems	`5095051 (Security Update)`	Important	Elevation of Privilege	Yes
Windows Server 2012	`5094042 (Monthly Rollup)`	Important	Elevation of Privilege	Yes
Windows Server 2012 (Server Core installation)	`5094042 (Monthly Rollup)`	Important	Elevation of Privilege	Yes
Windows Server 2012 R2	`5094041 (Monthly Rollup)`	Important	Elevation of Privilege	Yes
Windows Server 2012 R2 (Server Core installation)	`5094041 (Monthly Rollup)`	Important	Elevation of Privilege	Yes
Windows Server 2016	`5094122 (Security Update)`	Important	Elevation of Privilege	Yes
Windows Server 2016 (Server Core installation)	`5094122 (Security Update)`	Important	Elevation of Privilege	Yes
Windows Server 2019	`5094123 (Security Update)`	Important	Elevation of Privilege	Yes
Windows Server 2019 (Server Core installation)	`5094123 (Security Update)`	Important	Elevation of Privilege	Yes
Windows Server 2022	`5094128 (Security Update)`	Important	Elevation of Privilege	Yes
Windows Server 2022 (Server Core installation)	`5094128 (Security Update)`	Important	Elevation of Privilege	Yes
Windows Server 2025	`5094125 (Security Update)`	Important	Elevation of Privilege	Yes
Windows Server 2025 (Server Core installation)	`5094125 (Security Update)`	Important	Elevation of Privilege	Yes

Patches

10 patches

Article	Type	Restart
`5094122`	Security Update	Yes
`5094123`	Security Update	Yes
`5094127`	Security Update	Yes
`5093998`	Security Update	Yes
`5094126`	Security Update	Yes
`5095051`	Security Update	Yes
`5094042`	Monthly Rollup	Yes
`5094041`	Monthly Rollup	Yes
`5094128`	Security Update	Yes
`5094125`	Security Update	Yes

Patch Diff

ghidriff + GhidraMCP verification · ntoskrnl.exe (KB5101650)

WMI integer underflow (CWE-191 -> CWE-787): nt!WmipQueryAllDataMultiple (IOCTL 0x22812C) and nt!WmipQuerySingleMultiple (IOCTL 0x228130) subtract an 8-aligned provider-reported size from a 32-bit remaining-output counter without checking it fits. A WMI instance whose serialized size R is not 8-aligned (slop) passes the requiredSize=(DataSize+73)&~7 gate yet wraps the counter (R - ALIGN8(R)); the next WNODE item is then serialized out of bounds past the kernel SystemBuffer, giving a controlled OOB write (used by the public G4sp4rCS exploit to corrupt sprayed npfs data queue entries -> arbitrary read -> SYSTEM token). VERIFIED 2026-07-20: the saturating-subtract fix ships in BOTH builds behind WIL flag Feature_1045423416; KB5101650 is a CFR flag enablement, not a code change — ghidriff shows 0 changes in the WMI path (70,713/70,714 functions matched, 6 unrelated churn).

Pre-patch version 10.0.26100.8737 Download

Post-patch version 10.0.26100.8875 Download

Function	Address	Change	Note
`nt!WmipQuerySingleMultiple`	`0x1407a4fc0 (pre-patch); vulnerable sub @ +0x401`	none (code identical in both builds) — fix enabled via Feature_1045423416 flag flip	IOCTL 0x228130 path; outRemaining -= alignedActualSize underflow; saturating subtract already compiled in pre-patch, dormant behind CFR flag. Verified via GhidraMCP decompilation of 10.0.26100.8737.
`nt!WmipQueryAllDataMultiple`	`vulnerable sub @ +0x29a`	none (code identical in both builds) — fix enabled via Feature_1045423416 flag flip	IOCTL 0x22812C path; same unchecked aligned-size subtraction; same flag-gated saturating pattern present pre-patch. Verified via GhidraMCP.
`Feature_1045423416__private_IsEnabledDeviceUsageNoInline / _IsEnabledFallback`	`0x14064a9d4 / 0x14064aa0c (pre-patch)`	present in both builds; flag STATE changed by KB5101650 (CFR enablement, data-side)	CFR kill-switch gating both saturating subtractions; state lives in servicing/rollout data outside function-diff scope
`Unrelated churn (6 code-changed)`		code	RtlpCheckFunctionPatchAppliedInOriginalImage, FsRtlpRequestShareableOplock, FsRtlpComputeShareableOplockState, SepSecureBootCorrectBcd, NtFilterBootOption, RtlpHpVsSlotCreate; 1 added: Feature_3244801339__private_IsEnabledFallback

View full diff report View RCA report Download PoC

Known Exploits

No known exploits have been linked for this CVE yet. When available, exploit references will be sourced from public repositories and may be unverified, incomplete, or non-functional. Always review code carefully before use in any environment.

Acknowledgments

Anonymous

References

MSRC Advisory MITRE NVD