Microsoft Defender Insufficient Granularity of Access Control Vulnerability (CVE-2026-33825)
Severity: high · Patch status: unknown · Since 2026-04-22 · CVE-2026-33825
Microsoft Defender contains an insufficient granularity of access control vulnerability that could allow an authorized attacker to escalate privileges locally. CISA added CVE-2026-33825 to its Known Exploited Vulnerabilities catalog on Apr 22, 2026, which means attackers are exploiting it in the wild. CISA reports known use in ransomware campaigns.
What to do
- Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- US federal agencies must remediate by May 6, 2026 (BOD 22-01); treat that as the outer limit.
Sources
All live incidents on Threat Watch
