Windows Bluetooth Service: Elevation of privilege via heap-based buffer overflow

Summary

A heap-based buffer overflow in the Windows Bluetooth Service allows an unauthenticated attacker to elevate privileges. The attack vector is adjacent, so the attacker must be within Bluetooth range of the affected device; no user interaction is required. The CVSS 3.1 score is 8.8 (High), with high impact on confidentiality, integrity and availability.

Affected

• Windows 10 Version 1607 (builds before 10.0.14393.9612)
• Windows 10 Version 1809 (builds before 10.0.17763.9376)
• Windows 10 Version 21H2 (builds before 10.0.19044.7807)
• Windows 10 Version 22H2 (builds before 10.0.19045.7807)
• Windows 11 Version 23H2 (builds before 10.0.22631.7652)
• Windows 11 Version 24H2 (builds before 10.0.26100.9711)
• Windows 11 Version 25H2 (builds before 10.0.26200.9711)
• Windows 11 Version 26H1 (builds before 10.0.28000.3231)
• Windows 11 Version 26H2 (builds before 10.0.26300.9711)
• Windows Server 2016, including Server Core (builds before 10.0.14393.9612)
• Windows Server 2019, including Server Core (builds before 10.0.17763.9376)
• Windows Server 2022 (builds before 10.0.20348.5761)

Fixed in

• Install the October 2026 security update for each affected system; the first fixed build is the upper bound of the affected range listed above.
• Patch references from third-party sources, not yet verified against MSRC: KB5126653 (Windows 11 23H2), KB5126646 (Windows Server 2025), KB5126651 (Windows 10 1809 and Server 2019).
• Fixed builds for Windows 10 22H2 and Windows 11 25H2, 26H1 and 26H2 are not confirmed in the available sources.

Workaround

Unknown. No workaround is documented in the available sources.

• Interim measure (not from the vendor): disable the Bluetooth service or radio by policy on endpoints and servers where Bluetooth is not required, until the update is applied.

Exploitation

• Not listed in the CISA Known Exploited Vulnerabilities catalog.
• CISA SSVC assessment: exploitation none, not automatable, total technical impact.
• One third-party mirror lists the vulnerability as not exploited; EPSS is about 0.6%.
• No public proof of concept was found in a limited search; this does not rule one out.

Our recommendation

• Apply the October 2026 Windows security update as part of the next regular update cycle, and sooner on laptops used in public places or while travelling.
• Prioritise Windows 10 1607 and 1809 systems and Windows Server 2016 and 2019; these may require extended security update licensing.
• Where Bluetooth is not needed, disable the Bluetooth service or radio by policy until patched.
• Verify all build numbers against the MSRC advisory before rollout and monitor for signs of exploitation.

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-2026-83777 msrc.microsoft.com
• Vulners NVD record CVE-2026-83777 vulners.com
• OpenCVE CVE-2026-83777 app.opencve.io
• Strix CVE-2026-83777 (third-party, unverified) www.strix.ai
• Senserva KB5126653 (third-party, unverified) senserva.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 31 Oct 2026, 18:31.