Sources: National Vulnerability Database, CVE.org, CISA KEV, FIRST EPSS
CVE-2026-96066 Overview
Stack-based buffer overflow in Windows Local Security Authority Subsystem Service (LSASS) allows an authorized attacker to elevate privileges locally.
Critical Impact
Affected Products
- Microsoft Windows Local Security Authority Subsystem Service (LSASS): see the vendor advisory for the exact affected versions
Discovery Timeline
- 2026-11-10: CVE-2026-96066 published to the National Vulnerability Database by secure@microsoft.com
- 2026-11-10: last updated in the NVD database
Technical Details for CVE-2026-96066
Vulnerability Analysis
CVE-2026-96066 is a Stack Buffer Overflow weakness (CWE-121: Stack Buffer Overflow) in Microsoft Windows Local Security Authority Subsystem Service (LSASS). Based on its CVSS vector, the flaw needs local or adjacent access, needs some level of access, and needs no user interaction. A write past the end of a stack buffer can corrupt control data.
With a CVSS base score of 7.8, apply the vendor fix and confirm exposure on internet facing and business critical assets first.
Root Cause
The weakness is classified as CWE-121: Stack Buffer Overflow. A write past the end of a stack buffer can corrupt control data.
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 low 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:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Detection Methods for CVE-2026-96066
Detection Strategies
- Inventory every instance of Microsoft Windows Local Security Authority Subsystem Service (LSASS) 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 Windows Local Security Authority Subsystem Service (LSASS) 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-2026-96066
Immediate Actions Required
- Apply the fixed version of Microsoft Windows Local Security Authority Subsystem Service (LSASS) 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 Windows Local Security Authority Subsystem Service (LSASS).
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
- CWE-121: Stack Buffer Overflow More CVEs with this weakness
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
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