CVE-2026-33825
Published 2026-04-14 · Updated 2026-07-24 · Source secure@microsoft.com
Summary
CVE-2026-33825 is a high-severity (CVSS 7.8) vulnerability in Microsoft Defender. CISA added it to the Known Exploited Vulnerabilities catalog on April 22, 2026, which means exploitation in the wild has been confirmed; US federal agencies had to remediate it by May 6, 2026. CISA also lists it as known to be used in ransomware campaigns, so it should be prioritised accordingly. Microsoft has 390 vulnerabilities in the KEV catalog, 117 of them linked to ransomware.
All 390 known-exploited Microsoft vulnerabilities →Description
Insufficient granularity of access control in Microsoft Defender allows an authorized attacker to elevate privileges locally.
CVSS vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CISA Known-Exploited Vulnerability
Product: Microsoft — Defender
Name: Microsoft Defender Insufficient Granularity of Access Control Vulnerability
Date added: 2026-04-22 · Due: 2026-05-06
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.