Microsoft Windows Bluetooth Service: Elevation of privilege via numeric truncation

Summary

A numeric truncation error (CWE-197) in the Windows Bluetooth Service allows an attacker with an existing local, low-privileged account to elevate privileges on the affected system. No user interaction is required. The CVSS 3.1 base score is 7.8 (High) with high impact on confidentiality, integrity and availability.

Affected

• Windows 10 Version 1809: 10.0.17763.0 to before 10.0.17763.9487
• Windows 10 Version 21H2: 10.0.19044.0 to before 10.0.19044.7846
• Windows 10 Version 22H2: 10.0.19045.0 to before 10.0.19045.7846
• Windows 11 Version 23H2: 10.0.22631.0 to before 10.0.22631.7711
• Windows 11 Version 24H2: 10.0.26100.0 to before 10.0.26100.9974
• Windows 11 Version 25H2: 10.0.26200.0 to before 10.0.26200.9974
• Windows 11 Version 26H1: 10.0.28000.0 to before 10.0.28000.3501
• Windows 11 Version 26H2: 10.0.26300.0 to before 10.0.26300.9974
• Windows Server 2019 (including Server Core): 10.0.17763.0 to before 10.0.17763.9487
• Windows Server 2022: 10.0.20348.0 to before 10.0.20348.5870
• Windows Server 2025 (including Server Core): 10.0.26100.0 to before 10.0.26100.33822

Note: The version list is taken from the CVE record and has not been verified against the MSRC advisory. ARM64 builds: Unknown.

Fixed in

• Fixed builds are the threshold builds listed under affected versions, per the CVE record. Verification against the MSRC advisory and KB article numbers: Unknown.

Workaround

• Unknown. No vendor workaround or mitigation was found.
• Restrict local logon rights and standard-user access where possible.

Exploitation

• No evidence of exploitation in the wild or of a public proof of concept was found at the time of research.
• CISA SSVC: Exploitation none, automatable no, technical impact total.
• The CVSS vector includes E:U (exploit code maturity unproven).

Our recommendation

• Install the November 2026 cumulative updates on all affected Windows systems, prioritising workstations and terminal servers with many local users.
• Verify the affected versions against the MSRC advisory before rollout.
• Check whether Windows 10 systems are still supported (for example through Extended Security Updates).
• Restrict local logon rights and standard-user access where possible.

Public exploits iAttack code is publicly available (PoC on GitHub, Metasploit or Exploit-DB).

PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.

Research sources

• Microsoft Security Update Guide: CVE-2026-88213 msrc.microsoft.com
• CVE Record CVE-2026-88213 (CVE.org) www.cve.org
• Strix CVE-2026-88213 (third-party aggregator) 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, 03:21.