CVE-2025-59207 — Windows Kernel Elevation of Privilege Vulnerability

Executive Summary

Untrusted pointer dereference in Windows Kernel allows an authorized attacker to elevate privileges locally.

Overview

7.8

CVSS HIGH

Important

MS Severity

Not Exploited

MS Exploit Status

Less Likely

MS Exploit Likelihood

Category Elevation of Privilege

Weakness CWE-822: Untrusted Pointer Dereference

Released Oct 14 2025

Last Updated Oct 14 2025

Publicly Disclosed No

CISA KEV Not Listed

Known Exploits None Known

EPSS Score 0.00396 — 0.32694 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

0.00396

probability of exploitation in the next 30 days

0.32694 percentile - updated 2026-08-14

View on FIRST.org

Affected Products

23 affected products

Product	KB Article	Severity	Impact	Restart Required
Windows 10 Version 1809 for 32-bit Systems	`5066586 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 1809 for x64-based Systems	`5066586 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 21H2 for 32-bit Systems	`5066791 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 21H2 for ARM64-based Systems	`5066791 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 21H2 for x64-based Systems	`5066791 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 22H2 for 32-bit Systems	`5066791 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 22H2 for ARM64-based Systems	`5066791 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 10 Version 22H2 for x64-based Systems	`5066791 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 11 Version 22H2 for ARM64-based Systems	`5066793 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 11 Version 22H2 for x64-based Systems	`5066793 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 11 Version 23H2 for ARM64-based Systems	`5066793 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 11 Version 23H2 for x64-based Systems	`5066793 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 11 Version 24H2 for ARM64-based Systems	`5066835 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 11 Version 24H2 for x64-based Systems	`5066835 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 11 Version 25H2 for ARM64-based Systems	`5066835 (Security Update)`	Important	Elevation of Privilege	Yes
Windows 11 Version 25H2 for x64-based Systems	`5066835 (Security Update)`	Important	Elevation of Privilege	Yes
Windows Server 2019	`5066586 (Security Update)`	Important	Elevation of Privilege	Yes
Windows Server 2019 (Server Core installation)	`5066586 (Security Update)`	Important	Elevation of Privilege	Yes
Windows Server 2022	`5066782 (Security Update)`	Important	Elevation of Privilege	Yes
Windows Server 2022 (Server Core installation)	`5066782 (Security Update)`	Important	Elevation of Privilege	Yes
Windows Server 2022, 23H2 Edition (Server Core installation)	`5066780 (Security Update)`	Important	Elevation of Privilege	Yes
Windows Server 2025	`5066835 (Security Update)`	Important	Elevation of Privilege	Yes
Windows Server 2025 (Server Core installation)	`5066835 (Security Update)`	Important	Elevation of Privilege	Yes

Patches

6 patches

Article	Type	Restart
`5066586`	Security Update	Yes
`5066791`	Security Update	Yes
`5066793`	Security Update	Yes
`5066835`	Security Update	Yes
`5066782`	Security Update	Yes
`5066780`	Security Update	Yes

Patch Diff

ghidriff · prjflt.sys (KB5066835)

Untrusted pointer dereference (CWE-822) in the Windows Projected File System minifilter prjflt.sys PrjfCopyAsPlaceHolder, local EoP. An unprivileged user reaches PrjfCopyAsPlaceHolder via PrjfPortMessage -> PrjfWritePlaceholderInformationHandler, passing a _PRJ_PLACEHOLDER_INFO whose inline SecurityDescriptor (at PlaceholderInfo+SdOffset) is fully attacker-controlled. PRE: PrjfCopyAsPlaceHolder passes that raw user SecurityDescriptor straight to FltCreateFileEx2; because the create runs with PreviousMode == KernelMode, the downstream nt!SeCaptureSecurityDescriptor does NOT range-check the SD's Owner/Group/Sacl/Dacl fields, so they can point to arbitrary kernel addresses that are later dereferenced. Diff of prjflt.sys 10.0.26100.6725 -> .6899 (Oct 14 2025, KB5066835) confirms the fix: gated behind CFR flag Feature_2983238971, PrjfCopyAsPlaceHolder now pre-captures the user SD with SeCaptureSecurityDescriptor((PlaceholderInfo+0x44)+base, 1, 1) using PreviousMode = UserMode (arg 1), which validates the pointer fields and produces a sanitized self-relative kernel copy before FltCreateFileEx2, then frees it with SeReleaseSecurityDescriptor(local_f8, 1, 1). Note: our diff shows Feature_2983238971 (build/arch); PrjfWritePlaceholderInformationHandler and PrjfUpdatePlaceholderIfNeededHandler also gained the gate.

Pre-patch version 10.0.26100.6725 Download

Post-patch version 10.0.26100.6899 Download

Function	Address	Change	Note
`PrjfCopyAsPlaceHolder`	`code change`	code (user SecurityDescriptor now captured as UserMode before FltCreateFileEx2, CFR-gated)	Pre: raw user SD (PlaceholderInfo+SdOffset) passed to FltCreateFileEx2 while PreviousMode==KernelMode -> SeCaptureSecurityDescriptor skips Owner/Group/Sacl/Dacl range checks -> arbitrary kernel pointer deref. Post (Feature_2983238971): iVar4 = SeCaptureSecurityDescriptor((ulonglong)(uint)(param_1+0x44)+param_2, 1, 1) captures/validates the SD as UserMode; on cleanup SeReleaseSecurityDescriptor(local_f8, 1, 1) frees the captured copy.
`PrjfWritePlaceholderInformationHandler`	`code change`	code (CFR-gated caller path)	Caller that routes the user placeholder message to PrjfCopyAsPlaceHolder; gained the Feature_2983238971 gate.
`SeCaptureSecurityDescriptor`	`import`	newly called	SeCaptureSecurityDescriptor / SeReleaseSecurityDescriptor are now imported and called by PrjfCopyAsPlaceHolder to capture and release the user SD as UserMode.
`Feature_2983238971`	`gate`	added (CFR gate)	CFR flag gating the SeCaptureSecurityDescriptor(UserMode) capture path; the original raw-SD path still ships when disabled.

View full diff report View RCA report

Attack Path

A user-controlled placeholder SecurityDescriptor is passed to file creation under KernelMode, so its pointer fields are dereferenced without range checks

Derived from the patch delta: the checks added by the vendor identify which fields crossed a trust boundary unvalidated. Reachability and privilege are taken from the call chain in the RCA report.

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

ChenJian with Sea Security Orca Team

References

MSRC Advisory MITRE NVD