Windows Defender Triple Zero-Day: BlueHammer, RedSun, and UnDefend Actively Exploited in the Wild
Three critical zero-day vulnerabilities — BlueHammer (CVE-2026-33825), RedSun, and UnDefend — have been discovered in Windows Defender's remediation engine. All three allow local privilege escalation to SYSTEM level...
Three Windows Defender Zero-Days Exploited in the Wild: BlueHammer Patched, RedSun and UnDefend Still Unpatched
A security researcher dropped three Windows Defender zero-day exploits in 13 days — BlueHammer (CVE-2026-33825), RedSun, and UnDefend. All three are now confirmed active in live attacks, with...
Microsoft April 2026 Patch Tuesday: Actively Exploited SharePoint Zero-Day Among 167 Fixes
Microsoft's April 2026 Patch Tuesday patches 167 vulnerabilities including an actively exploited SharePoint Server zero-day (CVE-2026-32201) and a publicly disclosed Windows Defender race condition (CVE-2026-33825). Security teams should...
CVE-2026-39987: Marimo RCE Zero-Day Exploited Within 10 Hours of Disclosure — 662 Attacks Recorded
A critical unauthenticated RCE vulnerability in the Marimo Python notebook framework (CVE-2026-39987) was actively exploited just 10 hours after public disclosure. Sysdig recorded 662 exploit events over four...
Google Patches Actively Exploited Chrome Zero-Day CVE-2026-5281 — CISA Deadline Hits Today
Google has patched a high-severity use-after-free zero-day in Chrome's WebGPU implementation (CVE-2026-5281) that is actively exploited in the wild. CISA set a mandatory federal remediation deadline of April...
Critical Marimo Python Notebook Zero-Day (CVE-2026-39987) Exploited Within 10 Hours of Disclosure
A critical pre-authentication RCE vulnerability (CVE-2026-39987, CVSS 9.3) in the popular Marimo Python notebook platform was weaponised within 10 hours of public disclosure. Attackers are actively harvesting credentials,...
Fortinet Issues Emergency Patch for Actively Exploited FortiClient EMS Zero-Day CVE-2026-35616
A critical zero-day vulnerability (CVE-2026-35616, CVSS 9.1) in Fortinet FortiClient EMS was exploited in the wild before Fortinet published its advisory. The pre-authentication flaw allows remote code execution...
PoC Exploit Leaked for Unpatched Windows Privilege Escalation Zero-Day ‘BlueHammer’
A disgruntled researcher has published a working exploit for BlueHammer, an unpatched Windows local privilege escalation zero-day that abuses Windows Defender's update mechanism. Fully patched Windows 10, 11,...