Tag: redsun

BlueHammer, RedSun, and UnDefend: Three Windows Defender Zero-Days Exploited in the Wild Three Windows Defender vulnerabilities disclosed as zero-days in April 2026 are now being actively exploited: BlueHammer, RedSun, and UnDefend. All three vulnerabilities were published without patches as Proof-of-Concept (PoC) exploits by an anonymous security researcher protesting their treatment by Microsoft’s Security Response Center. […]