Detect CVE-2026-21525 - Microsoft Windows NULL Pointer Dereference Exploitation in Sumo Logic CSE
Detects exploitation attempts and post-exploitation activity related to CVE-2026-21525, a NULL pointer dereference vulnerability in Microsoft Windows. This vulnerability is actively exploited in the wild (CISA KEV) and may allow attackers to achieve privilege escalation or code execution via memory corruption techniques targeting Windows kernel or user-mode components.
MITRE ATT&CK
Sumo Detection Query
_sourceCategory=windows/events OR _sourceCategory=windows/sysmon
| where _messagetime > now() - 86400000
| json auto
| where (EventID in ("1001", "1000", "41", "7045", "10"))
| where EventID matches "100[01]" and (Message matches /(?i)(lsass|svchost|csrss|winlogon|wininit)/)
OR EventID = "7045"
OR (EventID = "10" and Message matches /(?i)lsass/)
| eval risk_score = if(EventID = "1001" and Message matches /(?i)lsass/, 100,
if(EventID = "7045", 80,
if(EventID = "41", 70, 50)))
| where risk_score >= 50
| fields _messagetime, _sourceHost, EventID, Message, risk_score
| sort by risk_score desc, _messagetime descSumo Logic detection for CVE-2026-21525 exploitation patterns including Windows Error Reporting crash events targeting critical processes, unexpected kernel driver installations, and LSASS access anomalies.
Data Sources
Required Tables
False Positives & Tuning
- Legitimate application instability in development or staging environments generating crash reports
- Endpoint security or monitoring tools registering as drivers during installation or update
- Windows kernel patches or hotfixes that temporarily cause process restarts
Other platforms for CVE-2026-21525
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 1Simulate Windows Process Crash via WER Trigger
Expected signal: EventID 1001 in Windows Application Event Log with FaultingApplicationName=CrashTest.exe and ExceptionCode=C0000005; Sysmon EventID 1 for process creation; EDR process termination event with non-zero exit code
- Test 2Load Unsigned Test Driver to Simulate Kernel Exploitation Activity
Expected signal: EventID 7045 in Windows System Event Log with ServiceName=CVE202621525TestDriver and ServiceType=kernel mode driver; Sysmon EventID 12/13 for registry modifications under HKLM\SYSTEM\CurrentControlSet\Services
- Test 3LSASS Access Simulation via ProcDump
Expected signal: Sysmon EventID 10 (ProcessAccess) with TargetImage=lsass.exe and GrantedAccess including 0x1FFFFF or 0x1010; Windows Defender EventID 1121 if credential protection rules are enabled; EDR LSASS access alert
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