Microsoft Windows PPPoE: Local privilege escalation via race condition
Summary
A race condition (CWE-362) in the Windows Point-to-Point Protocol over Ethernet (PPPoE) component allows an authorized local attacker to elevate privileges. The attacker needs a valid local account and must win a timing race, which makes exploitation harder. A successful attack could give the attacker high impact on confidentiality, integrity and availability of the affected system.
Affected
- Windows 10 Version 1607, 1809, 21H2 and 22H2
- Windows 11 Version 23H2, 24H2, 25H2, 26H1 and 26H2
- Windows Server 2016, 2019 and 2022, including Server Core installations
Build ranges per the Microsoft CNA record: Windows 10 1607 before 10.0.14393.9688; 1809 before 10.0.17763.9487; 21H2 before 10.0.19044.7846; 22H2 before 10.0.19045.7846; Windows 11 23H2 before 10.0.22631.7711; 24H2 before 10.0.26100.9974; 25H2 before 10.0.26200.9974; 26H1 before 10.0.28000.3501; 26H2 before 10.0.26300.9974; Server 2016 before 10.0.14393.9688; Server 2019 before 10.0.17763.9487; Server 2022 before 10.0.20348.5870.
Unknown: Whether Server 2025 or other products are affected. Verify on the MSRC page.
Fixed in
- Microsoft security update released with the November 2026 Patch Tuesday (10 November 2026).
- Unknown: The specific KB number for each Windows version. Check the MSRC page.
Workaround
- Unknown. No vendor workaround or mitigation was found. Do not assume one exists.
Exploitation
- No evidence of exploitation found.
- No public proof of concept found.
- CISA SSVC assessment: exploitation none, automatable no, technical impact total.
- CVE record exploit maturity: Unproven.
- No evidence found that it is listed in CISA KEV (not checked directly).
Our recommendation
- Install the November 2026 security update on all affected systems, prioritising multi-user systems, terminal servers and RDS servers.
- Confirm the fixed build for each operating system in the MSRC table.
- Restrict local logon rights and review accounts with local access.
- Monitor endpoints and servers for unexpected privilege changes until patching is complete.
Information from Microsoft (Patch Tuesday November 2026)
- Severity (Microsoft)
- Important
- Impact
- Elevation of privilege – Windows Point-to-Point Protocol over Ethernet (PPPoE)
- Status on Patch Tuesday
- Neither exploited nor publicly disclosed
- Exploitability assessment
- Exploitation less likely
- Product family
- Windows, Windows ESU (Extended Security Updates)
- Updates (KB)
- KB5131291, KB5131085, KB5131096, KB5131090, KB5131087, KB5132061
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Update Guide: CVE-2026-105511 msrc.microsoft.com
- CVE Record: CVE-2026-105511 www.cve.org
- Windows 11 KB5132061 and KB5131087 November 2026 patch coverage www.anoopcnair.com
- Microsoft November 2026 Patch Tuesday coverage (Digital Citizen) www.digitalcitizen.life
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, 09:45.
Original description (NVD)
Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Point-to-Point Protocol over Ethernet (PPPoE) 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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