Detect Microsoft Windows Improper Privilege Management (CVE-2026-21533) in Sumo Logic CSE
Detects exploitation of CVE-2026-21533, a Microsoft Windows Improper Privilege Management vulnerability (CWE-269) listed in CISA's Known Exploited Vulnerabilities catalog. Successful exploitation allows a local attacker to elevate privileges on a compromised Windows system. Detection focuses on anomalous privilege token manipulation, unexpected service/process privilege escalation, and suspicious access patterns consistent with local privilege escalation techniques.
MITRE ATT&CK
- Tactic
- Privilege Escalation Persistence
Sumo Detection Query
_sourceCategory=windows/security
| where EventID in ("4672", "4673", "4674")
| where !matches(SubjectUserName, "*$")
| where SubjectUserName != "SYSTEM"
| parse regex field=PrivilegeList "(?<Privilege>Se[A-Za-z]+Privilege)" multi
| where Privilege in ("SeDebugPrivilege", "SeTcbPrivilege", "SeLoadDriverPrivilege", "SeAssignPrimaryTokenPrivilege", "SeTakeOwnershipPrivilege")
| timeslice 1h
| stats count as PrivEscCount, values(Privilege) as Privileges, values(ProcessName) as Processes by SubjectUserName, Computer, _timeslice
| where PrivEscCount > 2
| sort by PrivEscCount descSumo Logic query detecting repeated sensitive privilege use by non-system interactive accounts, which may indicate privilege escalation exploitation of CVE-2026-21533.
Data Sources
Required Tables
False Positives & Tuning
- Automated patch management systems triggering privilege events during update cycles
- Antivirus and EDR products requiring SeDebugPrivilege to monitor running processes
- Development and build pipelines that compile or sign code requiring elevated privileges
- Helpdesk remote-access tools that use impersonation tokens during support sessions
Other platforms for CVE-2026-21533
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 1Token Impersonation via SeDebugPrivilege
Expected signal: Windows Security Event ID 4673 (SeDebugPrivilege requested) and 4688 (new process: powershell.exe) with Medium integrity initiating a SeDebugPrivilege request.
- Test 2Process Launch at High Integrity from Medium Integrity Parent
Expected signal: Event ID 4688 showing cmd.exe launched at High integrity (MandatoryLabel S-1-16-12288) with schtasks.exe as the initiating process from a Medium-integrity user session.
- Test 3Sensitive Privilege Enumeration via Token Inspection
Expected signal: Event ID 4688 for cmd.exe and powershell.exe, potential Event ID 4672 if running in an elevated session. Process command line arguments visible in EDR telemetry.
Unlock Pro Content
Get the full detection package for CVE-2026-21533 including response playbook, investigation guide, and atomic red team tests.