Detect Microsoft Windows Information Disclosure (CVE-2026-20805) in CrowdStrike LogScale
Detects exploitation of CVE-2026-20805, a Microsoft Windows information disclosure vulnerability (CWE-200) that allows attackers to access sensitive memory or kernel data. This vulnerability is actively exploited in the wild (CISA KEV). Successful exploitation may expose credentials, memory contents, or system information that enables privilege escalation or lateral movement.
MITRE ATT&CK
LogScale Detection Query
#event_simpleName IN ("ProcessRollup2", "SyntheticProcessRollup2", "DnsRequest")
| TargetProcessId != null
| (CommandLine = "*NtQuerySystemInformation*" OR CommandLine = "*ZwQuerySystemInformation*" OR CommandLine = "*ReadProcessMemory*" OR CommandLine = "*VirtualQueryEx*" OR ImageFileName = "*lsass.exe")
| IntegrityLevel IN ("LOW_INTEGRITY", "MEDIUM_INTEGRITY")
| groupBy([ComputerName, UserName, FileName, CommandLine, IntegrityLevel, ImageFileName], function=count(), as=EventCount)
| EventCount >= 1
| join kind=inner (
#event_simpleName = "PeFileWritten"
| (TargetFileName = "*\\SAM" OR TargetFileName = "*\\SECURITY" OR TargetFileName = "*ntds.dit" OR TargetFileName = "*lsass*")
| groupBy([ComputerName, UserName, TargetFileName], function=count(), as=FileAccessCount)
) on ComputerName, UserName
| project ComputerName, UserName, FileName, CommandLine, IntegrityLevel, ImageFileName, EventCount, TargetFileName, FileAccessCount
| sort(EventCount, order=desc)CrowdStrike Falcon CQL detecting CVE-2026-20805 by correlating low/medium integrity process events invoking Windows kernel information disclosure APIs with sensitive file write or access events targeting credential stores, joined on host and user context.
Data Sources
Required Tables
False Positives & Tuning
- CrowdStrike sensor itself or other security agents performing kernel-level enumeration for threat prevention
- Software development tools (debuggers, profilers) that access process memory during application testing
- IT management platforms performing authorized system configuration reads across managed endpoints
- Backup and recovery agents that access sensitive system files with appropriate entitlements
Other platforms for CVE-2026-20805
Testing Methodology
Validate this detection against 3 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.
- Test 1NtQuerySystemInformation via PowerShell P/Invoke
Expected signal: Sysmon Event ID 1 (Process Create) for powershell.exe; Windows Event ID 4688 if process command line auditing is enabled; EDR process telemetry capturing the PowerShell invocation with P/Invoke patterns.
- Test 2LSASS Handle Open with VM_READ Access
Expected signal: Sysmon Event ID 10 (ProcessAccess) with TargetImage=lsass.exe, GrantedAccess=0x0010 (PROCESS_VM_READ), SourceImage=powershell.exe; Windows Security Event ID 4656 for handle request to LSASS process object.
- Test 3Sensitive Registry Hive Access from Low Integrity Context
Expected signal: Windows Security Event ID 4663 with ObjectName containing SECURITY hive path; Sysmon Event ID 1 for process creation with low integrity level token; Event ID 4656 for registry key open with sensitive access mask.
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