Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
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AccessObtain local authenticated access
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DeliveryRun crafted program invoking Win32k interface
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ExploitTrigger heap-based buffer overflow in kernel
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ExecutionCorrupt kernel heap for code execution
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ImpactElevate privileges to SYSTEM
Vulnerability Assessment
| Weakness |
CWE
ASVS 5.0
V15 - Secure Coding and Architecture Heap buffer bounds checking
MITRE ATT&CK
1 technique across 1 tactic: Execution The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Exploitation Conditions | Exploitation requires the attacker to already possess local, authenticated low-privilege access to the target Windows host (PR:L, AV:L) and the ability to execute a crafted program that reaches the vulnerable Win32 kernel subsystem code path; no user interaction and no special non-default configuration are indicated. Limiting factors: the attack cannot be performed remotely or network-side, it presupposes an existing foothold on the machine, and it affects the specific Windows client and server builds below the patched versions listed in the EUVD data (e.g. Windows 11 24H2 below 10.0.26100.9711, Windows Server 2025 below 10.0.26100.33650). CISA SSVC rates it Automatable=no, so it does not lend itself to scripted mass exploitation. |
| Impact | This is a credible but not emergency-level priority. The CVSS 3.1 vector (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H, base 7.8 HIGH) describes a local privilege-escalation flaw requiring low-level authenticated access (PR:L) with low attack complexity and no user interaction, yielding total confidentiality, integrity and availability impact on the affected kernel subsystem. All signals are internally consistent: the description ('authorized attacker to elevate privileges locally') aligns with AV:L and PR:L, and CISA's SSVC framework reinforces this with Exploitation=none, Automatable=no, and Technical Impact=total - i.e. severe impact but no observed exploitation and not amenable to mass automation (typical of a local EoP that needs prior code execution on the host). There is no CISA KEV listing and no public POC referenced, so exploitation status is 'no public exploit identified at time of analysis.' Net assessment: a real patch-worthy kernel EoP useful as a post-compromise/privilege-escalation link in a chain, but given local-only vector, authentication requirement, SSVC Automatable=no, and absence of KEV/POC, it is a routine-priority patch rather than a drop-everything issue. No conflicting signals were found; the main unknown is real-world exploitation, which is currently unobserved. |
| Exploit ScenarioDerived | An attacker who already has a foothold on a Windows host as a standard authenticated user (e.g. via phishing or a compromised service account) runs a crafted program that triggers the heap-based buffer overflow in the Win32 kernel subsystem, corrupting kernel heap memory to execute code at SYSTEM and fully control the machine. No user interaction is required and attack complexity is low, but execution must occur locally; no public exploit code has been identified at the time of analysis. |
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Alert meAnalysisAIv1 – Oct 14, 2026
Local privilege escalation in the Microsoft Windows Win32 kernel subsystem allows an attacker who already holds low-privilege local access on a Windows host to corrupt heap memory and gain SYSTEM-level code execution. The flaw is a heap-based buffer overflow (CWE-122) rated CVSS 7.8 with a vector of AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H, meaning the attacker must be authenticated locally (PR:L, AV:L) and needs to run a crafted program that reaches the vulnerable kernel code path, with no user interaction required. There is no public exploit identified at time of analysis, CISA's SSVC assessment records Exploitation=none and Automatable=no, and vendor-released patches are available for all affected Windows client and server builds.
RemediationAI
Vendor-released patch: apply the Microsoft security update that brings each Windows build to or above the fixed levels listed in the MSRC advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-70060 - Windows 11 24H2 to 10.0.26100.9711, 23H2 to 10.0.22631.7652, 25H2 to 10.0.26200.9711, 26H1 to 10.0.28000.3231, 26H2 to 10.0.26300.9711, Windows 10 21H2/22H2 to 10.0.19044.7807, Windows 10 1809 to 10.0.17763.9376, Windows 10 1607 to 10.0.14393.9612, Windows Server 2025 to 10.0.26100.33650, Windows Server 2022 to 10.0.20348.5761, Windows Server 2019 to 10.0.17763.9376, Windows Server 2016 to 10.0.14393.9612, Windows Server 2012 R2 to 6.3.9600.23470, and Windows Server 2012 to 6.2.9200.26434. Prioritize internet-facing, multi-user, and remote-desktop session hosts, where low-privilege local access is easiest for an attacker to obtain through a separate initial-access flaw. Where patching must be staged, compensating controls include enforcing least privilege and removing unnecessary local interactive or service-account logon rights so that fewer principals can trigger the vulnerable code path, restricting execution of untrusted binaries through AppLocker or WDAC (which reduces the ability to deliver the crafted program but adds application-management overhead and can break legitimate unsigned tooling), and enabling kernel-level exploit protections such as Exploit Guard, Arbitrary Code Guard, and Code Integrity Guard, though these raise the exploitation bar rather than closing the underlying overflow. Monitor EDR telemetry for suspicious local processes gaining SYSTEM-level tokens or unusual win32k-related crashes as a detection backstop until the update is deployed everywhere.
Affected VersionsENISA
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 20 packages in euvd
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
The root cause is a heap-based buffer overflow (CWE-122) inside the Win32 kernel subsystem (win32k), the kernel-mode component that services windowing, GDI, and user-object operations on behalf of user-mode processes. Because the vulnerable code executes at kernel privilege while accepting input from a low-privileged caller, a suitable crafted call sequence can overrun a heap allocation, corrupt adjacent kernel structures, and ultimately redirect execution in kernel context. The CVSS vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H characterizes a local, low-complexity, low-privilege, no-interaction attack that yields high confidentiality, integrity, and availability impact while remaining within the same security authority (S:U) - the classic local privilege escalation profile used post-compromise to move from a standard user, service account, or sandboxed process to full administrative control of the host. Windows kernel privilege escalation bugs in this class are attractive to attackers with an existing foothold because they bypass the privilege boundary that normally protects the operating system's most sensitive data and functions.
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Local privilege escalation by an already-authenticated low-privilege user (AV:L, PR:L), no user interaction, low complexity, with kernel compromise yielding full C/I/A impact.
Primary rating from Vendor (microsoft).
CVSS VectorVendor: microsoft
Lifecycle Timeline
2DescriptionCVE.org
Heap-based buffer overflow in Windows Win32 Kernel Subsystem allows an authorized attacker to elevate privileges locally.
Executive ViewAI
A high-severity local privilege escalation flaw in the Microsoft Windows Win32 kernel subsystem allows anyone who already has a low-privilege account on a Windows machine to elevate to full SYSTEM control, compromising the confidentiality, integrity, and availability of the host. Because the attacker must already be logged in locally, the practical risk for the organization is that any compromised user account, contractor laptop, VDI session, or shared workstation becomes a stepping stone to full machine takeover. Leadership should care because SYSTEM-level access on endpoints is the standard prerequisite for disabling security tooling, harvesting credentials, and moving laterally toward servers and data. No public exploit has been identified at time of analysis and vendor patches are available, so this is a manageable, time-bound remediation task rather than an active incident.
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Threat Intelligence Overview
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
A buffer overflow occurs when a program writes more data to a memory buffer than it was allocated to hold, causing the excess data to spill into adjacent memory regions.
A heap overflow occurs when a program writes data beyond the bounds of a buffer allocated in the heap memory region.
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EUVD-2026-99144
GHSA-7rrq-j4mq-qcvq
NVD
CVE.org
EPSS
Vulnrichment
Exploit-DB