CVE-2026-33825: Microsoft Defender Insufficient Granularity of Access Control Vulnerability
Microsoft Defender contains an insufficient granularity of access control vulnerability that could allow an authorized attacker to escalate privileges locally.
| Vendor | Microsoft |
|---|---|
| Product | Defender |
| Date added to KEV | 2026-04-22 |
| Due date (BOD 22-01) | 2026-05-06 |
| Known ransomware campaign use | Known |
| CWE | CWE-1220 |
| Required action | Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. |
What to do
- Identify every instance of Microsoft Defender in your environment (asset inventory, EDR, vulnerability scanner).
- Apply CISA's required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- Federal civilian agencies must act by 2026-05-06 under BOD 22-01; other organizations can use the same date as a target.
- Because ransomware use is known, check for signs of compromise and confirm backups are offline and tested.
- Check the vendor advisory and NVD entry linked below for affected versions, then record the fix in your change log.
This CVE is flagged by CISA as known to be used in ransomware campaigns. Rehearse your response before you need it: Ransomware tabletop exercise kit (Runbook Foundry).