EUVD-2026-43769
GHSA-8mgw-7pfh-qv6c
Severity by source
AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Local EoP needing an existing standard-user foothold gives AV:L/PR:L, no UI, low complexity, and kernel compromise yields full C/I/A impact with unchanged scope.
Primary rating from Vendor (microsoft).
CVSS VectorVendor: microsoft
Lifecycle Timeline
2DescriptionCVE.org
Use after free in Windows Kernel Mode Driver allows an authorized attacker to elevate privileges locally.
AnalysisAI
Local privilege escalation in the Windows Kernel Mode Driver affects Windows 11 (24H2, 25H2, 26H1) and Windows Server 2025, where a use-after-free (CWE-416) lets an already-authenticated local attacker corrupt kernel memory and elevate to SYSTEM. Reported by Microsoft with a patch already available; there is no public exploit identified at time of analysis and it is not listed in CISA KEV. The CVSS 7.8 (AV:L/PR:L) reflects a high-impact but locally-scoped flaw requiring an existing foothold on the host.
Technical ContextAI
The vulnerability lives in a Windows kernel-mode driver - code running in ring 0 with full system privileges. CWE-416 (Use After Free) means the driver continues to reference an object after its backing memory has been freed; an attacker who reallocates that freed slot with attacker-controlled data can steer kernel execution or corrupt kernel structures, typically to overwrite a process token and gain SYSTEM. The CPE set identifies the affected platforms precisely: Windows 11 Version 24H2, 25H2, and 26H1, plus Windows Server 2025 including the Server Core installation. Because kernel drivers share a single address space, a successful UAF grants complete control of the machine rather than a sandboxed impact.
RemediationAI
Apply the Microsoft security update for CVE-2026-58602 delivered through Windows Update / WSUS / the Microsoft Update Catalog for each affected platform (Patch available per vendor advisory); the exact fixed build numbers are enumerated at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-58602 and should be applied to all Windows 11 24H2/25H2/26H1 and Windows Server 2025 (including Server Core) systems. No standalone workaround toggles the kernel driver off, so patching is the only complete fix; as compensating controls until the update lands, restrict local/interactive and RDP logon to trusted administrators (reducing who can run the required local code), enforce least privilege so fewer accounts hold an interactive foothold, and use application allowlisting (WDAC/AppLocker) to block untrusted binaries that would deliver the exploit - the trade-off being added administrative overhead and potential friction for legitimate local users and admin tooling.
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Same weakness CWE-416 – Use After Free
View allSame technique Denial Of Service
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External POC / Exploit Code
Leaving vuln.today