Windows LSASS: Heap-based buffer overflow allows local privilege escalation
Summary
A heap-based buffer overflow and race condition in the Windows Local Security Authority Subsystem Service (LSASS) allow an authorized local user to elevate privileges. The attack requires a local logon and high attack complexity. Successful exploitation could give an attacker full control over confidentiality, integrity and availability of the affected system.
Affected
- Windows 10 Version 1607 (before 10.0.14393.9688)
- Windows 10 Version 1809 (before 10.0.17763.9487)
- Windows 10 Version 21H2 (before 10.0.19044.7846)
- Windows 10 Version 22H2 (before 10.0.19045.7846)
- Windows 11 Version 23H2 (before 10.0.22631.7711)
- Windows 11 Version 24H2 (before 10.0.26100.9974)
- Windows 11 Version 25H2 (before 10.0.26200.9974)
- Windows 11 Version 26H1 (before 10.0.28000.3501)
- Windows 11 Version 26H2 (before 10.0.26300.9974)
- Windows Server 2016 (before 10.0.14393.9688)
- Windows Server 2019 (before 10.0.17763.9487)
- Windows Server 2022 (before 10.0.20348.5870)
Fixed in
- Windows 10 1607: 10.0.14393.9688
- Windows 10 1809: 10.0.17763.9487
- Windows 10 21H2: 10.0.19044.7846
- Windows 10 22H2: 10.0.19045.7846
- Windows 11 23H2: 10.0.22631.7711
- Windows 11 24H2: 10.0.26100.9974
- Windows 11 25H2: 10.0.26200.9974
- Windows 11 26H1: 10.0.28000.3501
- Windows 11 26H2: 10.0.26300.9974
- Windows Server 2016: 10.0.14393.9688
- Windows Server 2019: 10.0.17763.9487
- Windows Server 2022: 10.0.20348.5870
KB numbers were not verified.
Workaround
Unknown.
Exploitation
- CISA SSVC: exploitation none, automatable no, technical impact total.
- CVSS temporal vector indicates no known exploit code at publication (E:U).
- No evidence of in-the-wild exploitation or public proof-of-concept found. MSRC exploitation flags not verified.
Our recommendation
- Install the November 2026 cumulative update on all affected Windows systems as a priority, starting with workstations and servers where users log on interactively.
- Check for legacy builds (Windows 10 1607, 1809, 21H2) including LTSC and ESU devices, as they may receive updates on a different schedule.
- Verify the affected and fixed versions, including Windows 11 and Server coverage, on the MSRC advisory before rollout.
- Monitor for CISA KEV addition or public proof-of-concept code, which would raise the priority.
Information from Microsoft (Patch Tuesday November 2026)
- Severity (Microsoft)
- Important
- Impact
- Elevation of privilege – Windows Local Security Authority Subsystem Service (LSASS)
- Status on Patch Tuesday
- Neither exploited nor publicly disclosed
- Exploitability assessment
- Exploitation less likely
- Product family
- Windows, Windows ESU (Extended Security Updates)
- Updates (KB)
- KB5131085, KB5131090, KB5131096, KB5131080, KB5131077, KB5132061
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Update Guide: CVE-2026-88228 msrc.microsoft.com
- CVE Record: CVE-2026-88228 www.cve.org
- Microsoft Security Update Guide: CVE-2026-70231 (related LSASS advisory) msrc.microsoft.com
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 11 Nov 2026, 08:12.
Original description (NVD)
Heap-based buffer overflow in Windows Local Security Authority Subsystem Service (LSASS) allows an authorized attacker to elevate privileges locally.
NVD references (1)
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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