BlueHammer

Pierluigi Paganini July 01, 2026
CISA Warns BlueHammer Flaw Is Now Exploited in Ransomware Attacks

CISA confirms BlueHammer (CVE-2026-33825) is now used in ransomware attacks to gain SYSTEM privileges through Microsoft Defender. BlueHammer, tracked as CVE-2026-33825, has moved from proof-of-concept noise to real ransomware attacks in the wild, the US CISA confirms. BlueHammer allows attackers to escalate privileges locally in Microsoft Defender. The vulnerability, along with two other zero-days dubbed […]

Pierluigi Paganini April 18, 2026
Microsoft Defender under attack as three zero-days, two of them still unpatched, enable elevated access

Attackers exploit three Microsoft Defender zero-days, code-named BlueHammer, RedSun, and UnDefend, to gain elevated access. Attackers are exploiting three recently disclosed zero-day flaws in Microsoft Defender to gain higher privileges on compromised systems. The vulnerabilities, called BlueHammer, RedSun, and UnDefend, were revealed by a researcher known as Chaotic Eclipse after criticizing Microsoft’s handling of the […]

Pierluigi Paganini April 07, 2026
Experts published unpatched Windows zero-day BlueHammer

A researcher leaked the unpatched Windows zero-day “BlueHammer,” letting attackers gain SYSTEM rights; no patch exists yet. A disgruntled researcher released the BlueHammer Windows zero-day, a privilege escalation flaw that allows attackers to gain SYSTEM or admin rights, Bleeping Computer reports. The researcher privately reported the vulnerability to Microsoft but criticized the way the Microsoft’s Security […]