Executive Summary BlueHammer (CVE-2026-33825) is an eight-stage local privilege-escalation chain targeting the Windows Defender Antimalware Platform before 4.18.26030.3011. It does not grant initial access; an attacker needs standard-user code execution first. Still, in the lab, it reached NT AUTHORITY\SYSTEM, recovered domain-admin credentials from LSASS, and moved laterally via pass-the-hash. This is not memory corruption. It […]

CISA has added one new vulnerability to its Known Exploited Vulnerabilities (KEV) Catalog , based on evidence of active exploitation. CVE-2026-33825 Microsoft Defender Insufficient Granularity of Access Control Vulnerability This type of vulnerability is a frequent attack vector for malicious cyber actors and poses significant risks to the federal enterprise. Binding Operational Directive (BOD) 22-01: Reducing the Significant Risk of Known Exploited Vulnerabilities established the KEV Catalog as a living list of known Common Vulnerabilities and Exposures (CVEs) that carry significant risk to the federal enterprise. BOD 22-01 requires Federal Civilian Executive Branch (FCEB) agencies to remediate identified vulnerabilities by the due date to protect FCEB networks against active threats. See the BOD 22-01 Fact Sheet for more information. Although BOD 22-01 only applies to FCEB agencies, CISA strongly urges all organizations to reduce their exposure to cyberattacks by prioritizing timely remediation of KEV Catalog vulnerabilities as part of their vulnerability management practice. CISA will continue to add vulnerabilities to the catalog that meet the specified criteria . 

Microsoft Defender contains an insufficient granularity of access control vulnerability that could allow an authorized attacker to escalate privileges locally.