Windows 10 1607: Integer underflow in Bluetooth A2DP driver allows privilege escalation
Summary
Microsoft has published CVE-2026-83838, an integer underflow (CWE-191) in the Windows Bluetooth A2DP driver, which handles Bluetooth audio streaming. An attacker with low-privilege access on an adjacent network, in practice within Bluetooth range, can use it to gain elevated privileges. The CVSS base score is 8.0 (High). CISA SSVC lists no known exploitation and the CVE is not in the CISA KEV catalogue.
Affected
- Windows 10 Version 1607 (including Windows Server 2016 and Server Core) before 10.0.14393.9612
- Other Windows 10, Windows 11 and Windows Server editions are also listed in the CNA record; see the MSRC advisory
Fixed in
- Windows 10 Version 1607: build 10.0.14393.9612 or later (per CNA data; KB number unknown)
- Verify the fixed builds on the MSRC advisory before deployment
Workaround
- No vendor workaround found.
- Disable the Bluetooth radio or adapter on devices where Bluetooth is not needed.
Exploitation
- Not listed in CISA KEV.
- CISA SSVC: exploitation none, automatable no, technical impact total.
- EPSS about 0.5%.
- No public proof of concept found; this has not been fully verified.
Our recommendation
- Identify all Windows 10 1607 devices (including Server 2016), especially kiosks, POS, HMI and thin clients.
- Plan migration to a supported Windows version. According to the 4sysops source, 1607 Enterprise LTSB reaches end of extended support on 13 October 2026.
- If migration is not possible in time, check ESU eligibility. Devices without ESU may not receive this fix.
- Install the security update on supported systems as soon as possible, restrict Bluetooth use and monitor systems for signs of privilege escalation.
Information from Microsoft (Patch Tuesday October 2026)
- Severity (Microsoft)
- Important
- Impact
- Elevation of privilege – Windows Bluetooth A2DP driver
- Status on Patch Tuesday
- Neither exploited nor publicly disclosed
- Exploitability assessment
- Exploitation less likely
- Product family
- Windows, Windows ESU (Extended Security Updates)
- Updates (KB)
- KB5127648, KB5126651, KB5126655, KB5126657, KB5126646, KB5126653
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- MSRC Security Update Guide: CVE-2026-83838 msrc.microsoft.com
- NVD record mirror (Vulners) vulners.com
- CNA record mirror (Vulners) vulners.com
- OpenCVE: CVE-2026-83838 app.opencve.io
- Rapid7 / EPSS mirror (Vulners) vulners.com
- Windows 10 Enterprise LTSB 2016 end of support and ESU 4sysops.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 1 Nov 2026, 21:24.
Original description (NVD)
Integer underflow (wrap or wraparound) in Windows Bluetooth A2DP driver allows an authorized attacker to elevate privileges over an adjacent network.
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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