Csoonline
Critical Windows Shell Zero-Day Vulnerability Exploited
First seen 12 Feb 2026, 01:27 UTC
•



•85% similarity
•23.9
Share:
Export
Ask AI about this cluster
Analyzing cluster data...
Referenced clusters:
Something went wrong. Please try again.
Cluster AI
Ask questions about this threat cluster with AI-powered analysis.
Get Researcher $29.99/moArticle Content
Browse articles
Microsoft has released updates to address a critical zero-day vulnerability in Windows Shell, tracked as CVE-2026-21510, which is actively being exploited. This security flaw allows remote attackers to bypass essential protection mechanisms, affecting millions of Windows users. The vulnerability was published on February 10, 2026, and added to the CISA KEV due to active exploitation on the same day.
ThreatCluster AI
Timeline
2026-02-10
CVE-2026-21510 published
2026-02-10
CVE-2026-21510 added to CISA KEV (active exploitation)
2026-02-11
Microsoft released updates to address the vulnerability