CVE-2026-61355 Overview
CVE-2026-61355 is a heap-based buffer overflow (CWE-122) in the Windows Sensor Data Service. An authorized local attacker can corrupt heap memory to elevate privileges on the affected host. Microsoft rates the issue as High severity, and it affects a broad range of client and server Windows releases, including Windows 10, Windows 11, Windows Server 2022, and Windows Server 2025.
Successful exploitation yields high confidentiality, integrity, and availability impact on the compromised system. The flaw is not currently listed in the CISA Known Exploited Vulnerabilities catalog, and no public proof-of-concept exploit is available at the time of writing.
Critical Impact
A local, authenticated attacker can overflow the heap in the Windows Sensor Data Service to gain elevated privileges, enabling full compromise of the target endpoint.
Affected Products
- Microsoft Windows 10 21H2 and 22H2 (x86, x64, ARM64)
- Microsoft Windows 11 23H2, 24H2, 25H2, and 26H1 (x64, ARM64)
- Microsoft Windows Server 2022 and Windows Server 2025
Discovery Timeline
- 2026-08-11 - CVE-2026-61355 published to the National Vulnerability Database
- 2026-08-13 - Entry last modified in NVD
Technical Details for CVE-2026-61355
Vulnerability Analysis
The Windows Sensor Data Service (SensorDataService) collects and brokers sensor telemetry between hardware sensors and user-mode applications. CVE-2026-61355 is a heap-based buffer overflow within this service. When the service processes attacker-influenced input, it writes past the bounds of a heap allocation.
Because the service runs with elevated privileges, corrupting its heap allows an authenticated local attacker to influence execution flow or overwrite adjacent objects. Successful exploitation results in code execution at a higher integrity level than the calling user. This provides a direct path from a standard user account to SYSTEM-level control on the affected host.
Root Cause
The root cause is insufficient bounds checking on data written into a heap buffer within the Sensor Data Service. Under CWE-122, heap-based buffer overflows typically arise from arithmetic errors in size calculations, missing length validation on attacker-controlled fields, or incorrect assumptions about input structure. The specific vulnerable routine has not been disclosed by Microsoft.
Attack Vector
Exploitation requires local access and low-privilege authentication on the target host. No user interaction is needed. An attacker with an interactive session or a foothold obtained through phishing, malware, or credential theft interacts with the Sensor Data Service through its exposed IPC surface. Crafted input triggers the overflow and drives execution toward attacker-controlled data on the heap.
Refer to the Microsoft CVE-2026-61355 Advisory for authoritative technical details.
Detection Methods for CVE-2026-61355
Indicators of Compromise
- Unexpected crashes, restarts, or Windows Error Reporting entries for SensorDataService.dll or the hosting svchost.exe instance.
- New child processes spawned under the Sensor Data Service context, particularly cmd.exe, powershell.exe, or LOLBins invoked with SYSTEM privileges.
- Newly created services, scheduled tasks, or local accounts appearing shortly after Sensor Data Service anomalies.
Detection Strategies
- Hunt for process lineage where the Sensor Data Service host process spawns interactive shells or unsigned binaries.
- Monitor Windows Event Log IDs 1000 and 1001 for faulting modules associated with sensor components.
- Correlate local logon events with subsequent privilege changes or token elevation on the same host.
Monitoring Recommendations
- Baseline normal behavior of the Sensor Data Service across your fleet and alert on deviations such as unusual memory usage or crash frequency.
- Forward endpoint telemetry, service crash events, and process creation logs to a central analytics platform for retrospective hunting.
- Track patch compliance for the affected Windows builds and flag hosts still running vulnerable versions.
How to Mitigate CVE-2026-61355
Immediate Actions Required
- Apply the Microsoft security update referenced in the Microsoft CVE-2026-61355 Advisory to all affected Windows 10, Windows 11, Windows Server 2022, and Windows Server 2025 systems.
- Prioritize patching multi-user hosts, jump servers, and endpoints accessible via Remote Desktop, where local privilege escalation carries the greatest downstream risk.
- Audit local account membership and remove unnecessary interactive logon rights to reduce the population of users who can trigger the flaw.
Patch Information
Microsoft has published a security update through the Microsoft Security Response Center. Deploy the update via Windows Update, Windows Server Update Services (WSUS), Microsoft Intune, or Microsoft Configuration Manager. Validate installation by confirming the appropriate KB build number for each affected Windows release.
Workarounds
- Where the Sensor Data Service is not required (typical for servers and virtualized workloads without physical sensors), set the SensorDataService startup type to Disabled and stop the running service.
- Restrict local interactive and Remote Desktop logon rights through Group Policy to limit which accounts can attempt exploitation.
- Enforce application allowlisting to block untrusted binaries from executing in user contexts that could stage the exploit.
# Configuration example: disable Sensor Data Service where not needed
sc.exe config SensorDataService start= disabled
sc.exe stop SensorDataService
# Verify patch level on a Windows host
wmic qfe list brief /format:table
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
