EUVD-2026-43971
GHSA-ggv4-x2vr-w9jf
Severity by source
AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Adjacent Bluetooth range gives AV:A; no auth or interaction needed (PR:N/UI:N/AC:L); kernel-mode overflow yields total compromise, so C/I/A all High.
Primary rating from Vendor (microsoft).
CVSS VectorNVD
Lifecycle Timeline
5DescriptionNVD
Heap-based buffer overflow in Windows Bluetooth Port Driver allows an unauthorized attacker to execute code over an adjacent network.
AnalysisAI
Remote code execution in the Microsoft Windows Bluetooth Port Driver (bthport) allows an adjacent, unauthenticated attacker to run arbitrary code by triggering a heap-based buffer overflow over Bluetooth radio range. The flaw spans a wide range of Windows client and server builds, from Windows 10 1607 and Server 2012 through Windows 11 26H1 and Server 2025. There is no public exploit identified at time of analysis, EPSS is modest at 0.38% (30th percentile), and CISA SSVC currently marks exploitation as 'none', but the CVSS 8.8 rating and 'total' technical impact make this a high-priority patch.
Technical ContextAI
The vulnerability resides in the Windows Bluetooth Port Driver, the kernel-mode component (bthport.sys) that implements the core Bluetooth stack and parses Host Controller Interface (HCI) events and L2CAP/protocol data exchanged with paired or nearby Bluetooth peers. CWE-122 (Heap-based Buffer Overflow) indicates the driver allocates a heap buffer and then writes attacker-influenced data beyond its bounds - typically due to a missing or incorrect length validation when parsing an inbound Bluetooth frame. Because the code runs in kernel mode, corrupting the pool grants control over kernel memory, which is why the CVSS confidentiality/integrity/availability impacts are all High and SSVC technical impact is rated 'total'. The affected CPEs confirm the defect is present across nearly the entire supported Windows lineage (Windows 10 1607/1809/21H2/22H2, Windows 11 24H2/25H2/26H1, and Windows Server 2012 through 2025, including Server Core installations).
RemediationAI
Apply the Microsoft security update for CVE-2026-42975, which is available from the vendor; install the cumulative update that brings each affected build to or above its fixed revision, e.g. Windows 11 24H2 to 10.0.26100.8875, Windows 11 25H2 to 10.0.26200.8875, Windows Server 2022 to 10.0.20348.5386, Windows Server 2025 to 10.0.26100.33158, Windows Server 2012 to 6.2.9200.26226, and Windows Server 2012 R2 to 6.3.9600.23291, per the MSRC update guide at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-42975. Where patching must be delayed, reduce exposure by disabling the Bluetooth radio or the Bluetooth Support Service (bthserv) on systems that do not require it - this fully removes the attack surface but breaks Bluetooth peripherals - and on servers, which rarely use Bluetooth, disabling or physically removing Bluetooth adapters is a low-cost mitigation. Because the attack requires physical proximity, restricting device presence in sensitive areas and turning off Bluetooth discoverability further lowers, though does not eliminate, risk.
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Same weakness CWE-122 – Heap-based Buffer Overflow
View allSame technique Heap Overflow
View allShare
External POC / Exploit Code
Leaving vuln.today