Microsoft Windows: Heap-based buffer overflow in Xbox Gaming Services
Summary
The Xbox Gaming Services component in supported Windows 10, Windows 11 and Windows Server versions contains a heap-based buffer overflow. A local user with low privileges can exploit it to gain higher privileges, potentially up to SYSTEM. The attack requires local access and an existing user account, so the flaw is not directly reachable from the internet.
Affected
- Windows 10 Version 1607 and Windows Server 2016 (including Server Core): builds 10.0.14393.0 to below 10.0.14393.9688
- Windows 10 Version 1809 and Windows Server 2019 (including Server Core): builds 10.0.17763.0 to below 10.0.17763.9487
- Windows 10 Version 21H2: builds 10.0.19044.0 to below 10.0.19044.7846
- Windows 10 Version 22H2: builds 10.0.19045.0 to below 10.0.19045.7846
- Windows 11 Version 23H2: builds 10.0.22631.0 to below 10.0.22631.7711
- Windows 11 Version 24H2 and 25H2: builds 10.0.26100.0 to below 10.0.26100.9974 and 10.0.26200.0 to below 10.0.26200.9974
- Windows 11 Version 26H1: builds 10.0.28000.0 to below 10.0.28000.3501
- Windows 11 Version 26H2: builds 10.0.26300.0 to below 10.0.26300.9974
- Windows Server 2025: builds 10.0.26100.0 to below 10.0.26100.33822
- Version data taken from the CNA record; not yet verified against the MSRC page.
Fixed in
- Installation of the November 2026 cumulative update for each affected Windows build.
- Specific KB numbers: Unknown.
Workaround
Unknown. No vendor workaround has been identified.
Exploitation
- No evidence of exploitation in the wild found at the time of research.
- No public proof-of-concept found at the time of research.
- CISA SSVC assessment: exploitation none, automatable no, technical impact total.
- The CVSS vector includes exploit maturity E:U (unproven).
Our recommendation
- Install the November 2026 cumulative update on all affected Windows 10, 11 and Server systems, prioritising multi-user workstations, terminal servers and shared systems.
- Check whether Windows 10 1607 or 1809 systems are still in use and confirm their vendor support status.
- Limit local user accounts and remove unneeded local logons on shared systems.
- Monitor for unusual privilege changes and new SYSTEM-level processes, and re-check CISA KEV before relying on the exploitation status.
Information from Microsoft (Patch Tuesday November 2026)
- Severity (Microsoft)
- Important
- Impact
- Elevation of privilege – Xbox
- Status on Patch Tuesday
- Neither exploited nor publicly disclosed
- Exploitability assessment
- Exploitation more likely
- Product family
- Windows, Windows ESU (Extended Security Updates)
- Updates (KB)
- KB5131085, KB5131096, KB5131080, KB5131077, KB5132061, KB5132043
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- MSRC advisory CVE-2026-95874 msrc.microsoft.com
- CVE.org CNA record CVE-2026-95874 www.cve.org
- Qualys November 2026 Patch Tuesday review blog.qualys.com
- Third-party tracker CVE-2026-95874 (unverified version data) www.strix.ai
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, 03:08.
Original description (NVD)
Heap-based buffer overflow in Xbox 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.
Affected? We can help.
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