Sources: National Vulnerability Database, CVE.org, CISA KEV, FIRST EPSS
CVE-2026-103571 Overview
An elevation of privilege vulnerability exists when the Windows Cryptography Next Generation (CNG) Key Isolation service improperly handles memory. An attacker who successfully exploited this vulnerability could run processes in an elevated context. To exploit this vulnerability, an attacker would first have to gain execution on the victim system. An attacker could then run a specially crafted application to elevate privileges. The security update addresses the vulnerability by correcting how the Windows CNG Key Isolation Service handles memory.
Critical Impact
Affected Products
- Microsoft product: see the vendor advisory for the exact affected versions
Discovery Timeline
- 2026-11-10: CVE-2026-103571 published to the National Vulnerability Database by secure@microsoft.com
- 2026-11-10: last updated in the NVD database
Technical Details for CVE-2026-103571
Vulnerability Analysis
CVE-2026-103571 is a Security Vulnerability weakness (CWE-415) in Microsoft product. Based on its CVSS vector, the flaw needs local or adjacent access, needs some level of access, and needs no user interaction.
With a CVSS base score of 7, apply the vendor fix and confirm exposure on internet facing and business critical assets first.
Root Cause
The vendor description states: An elevation of privilege vulnerability exists when the Windows Cryptography Next Generation (CNG) Key Isolation service improperly handles memory. An attacker who successfully exploited this vulnerability could run processes in an elevated context. To exploit this vulnerability, an attacker would first have to gain execution on the victim system. An attacker could then run a specially crafted application to elevate privileges. The security update addresses the vulnerability by correcting how the Windows CNG Key Isolation Service handles memory.
Attack Vector
Based on the CVSS vector, the flaw needs local or adjacent access, needs some level of access, and needs no user interaction. Attack complexity is high complexity.
No exploitation in the wild is confirmed by CISA at the time of the last update. Check the references below for any vendor or researcher proof of concept.
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Detection Methods for CVE-2026-103571
Detection Strategies
- Inventory every instance of Microsoft product and compare the running version with the affected range above.
- Check external attack surface scans for internet facing instances of the component.
- Run an authenticated vulnerability scan once your scanner ships a check for this CVE.
Monitoring Recommendations
- Forward Microsoft product application, access and audit logs to your SIEM for retrospective hunting.
- Alert on new processes, configuration changes or outbound connections from the affected service.
- Track the vendor advisory and the CISA KEV catalog for changes in exploitation status.
How to Mitigate CVE-2026-103571
Immediate Actions Required
- Apply the fixed version of Microsoft product named in the vendor advisory.
- Prioritize internet facing and business critical instances first.
- Rescan after the change to confirm the exposure is closed.
Patch Information
Use the fixed version listed in the vendor advisory for Microsoft product.
Workarounds
- If patching must wait, restrict network access to the affected service and place it behind authentication or a web application firewall rule.
CWE References
Technical References
This entry is built directly from NVD, CISA KEV and EPSS data. Verify fixed versions in the vendor advisory before you deploy.
Frequently asked questions
Related CVEs
Access of resource using incompatible type ('type confusion') in Windows Shell allows an authorized attacker to elevate privileges locally.
Out-of-bounds read in Windows VMSwitch allows an authorized attacker to elevate privileges locally.
Null pointer dereference in Windows USM Communication Manager allows an authorized attacker to elevate privileges locally.
Use after free in Winsock allows an authorized attacker to elevate privileges locally.
Release of invalid pointer or reference in Windows Performance Monitor allows an unauthorized attacker to execute code over a network.
Use after free in Windows Credential User Interface allows an authorized attacker to elevate privileges locally.
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