EUVD-2026-43827
GHSA-68x7-6v3r-qfc7
Severity by source
AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Local authenticated attacker (AV:L/PR:L) must win a use-after-free race (AC:H), with full SYSTEM-level CIA impact and no scope change.
Primary rating from Vendor (microsoft).
CVSS VectorVendor: microsoft
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Lifecycle Timeline
2DescriptionCVE.org
Use after free in Windows Runtime allows an authorized attacker to elevate privileges locally.
AnalysisAI
Local privilege escalation in Windows Runtime (WinRT) on Windows 11 (24H2, 25H2, 26H1) and Windows Server 2025 allows an authenticated local user to gain higher privileges by exploiting a use-after-free memory-corruption flaw (CWE-416). Successful exploitation yields high confidentiality, integrity, and availability impact, effectively enabling escalation to SYSTEM-level control on the host. …
Unlock full vulnerability intelligence
- Risk assessment & exploitation conditions
- Attack chain visualization
- Remediation with exact patch versions
- Threat intelligence from 22 sources
- Personal watchlist & email alerts
Free forever · No credit card required
Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | Exploitation requires the attacker to already have authenticated, low-privileged local code execution on the target (PR:L, AV:L) - no remote or unauthenticated path exists. … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The CVSS 3.1 base score is 7.0 (High) with vector AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H - a local vector requiring existing low-level privileges and high attack complexity, but with full CIA impact once achieved. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | An attacker who has already obtained a low-privileged foothold on a Windows 11 or Server 2025 host - for example via phishing, a compromised standard user account, or a malicious app - runs code that triggers the use-after-free in Windows Runtime, races to reclaim the freed allocation with attacker-controlled data, and corrupts memory to execute in a privileged context, elevating to SYSTEM. The high attack complexity means the exploit may require multiple attempts to win the timing/heap race; no public POC is currently identified. |
| Remediation | Apply the vendor patch: Patch available per Microsoft advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-50323 - install the corresponding monthly cumulative update (KB) for your specific SKU (Windows 11 24H2/25H2/26H1 or Windows Server 2025, including Server Core) as listed in the MSRC update guide; an exact fix build number was not included in the input data and should be taken from that advisory. … Detailed patch versions, workarounds, and compensating controls in full report. |
Recommended ActionAI
Within 24 hours, identify and inventory all Windows 11 (24H2, 25H2, 26H1) and Windows Server 2025 systems in your environment. …
Sign in for detailed remediation steps and compensating controls.
Threat intelligence, references, and detailed analysis are available after sign-in.
More in Windows 11 Version 24H2
View allLocal privilege escalation in the Microsoft Windows Kernel allows an unauthorized attacker to gain elevated (SYSTEM-leve
Local privilege escalation in the Windows Win32K kernel subsystem (CWE-122 heap-based buffer overflow) lets an already-a
Local privilege escalation in the Windows Kernel lets an already-authenticated attacker corrupt kernel memory via a use-
Local code execution in the Windows DHCP Client service stems from a use-after-free (CWE-416) memory-corruption flaw aff
Local code execution in the Microsoft Message Queuing (MSMQ) Queue Manager affects a broad range of Windows client and s
Elevation of privilege in the Windows NTFS file-system driver lets an already-authenticated local user escalate to SYSTE
Local code execution in the Windows Media component of supported Windows 10, Windows 11, and Windows Server (2016 throug
Local privilege escalation in the Microsoft Windows Kernel allows an already-authenticated attacker to elevate to SYSTEM
Elevation of privilege in the Windows Hyper-V virtual network switch (VMSwitch) lets an authenticated attacker operating
Remote code execution in the Windows Server Network driver stems from a race condition (CWE-362) that lets an unauthoriz
Remote code execution in Microsoft Windows Remote Desktop (RDP) allows an unauthorized network attacker to run arbitrary
Remote code execution in Microsoft Windows Message Queuing (MSMQ) allows an unauthenticated attacker to run arbitrary co
Same weakness CWE-416 – Use After Free
View allSame technique Use After Free
View allShare
External POC / Exploit Code
Leaving vuln.today