CVE-2021-21186
✓ Confirmed 0-Day
Triaged: March 20, 2026
2 articles
EPSS Score
Source: FIRST.org · 2026-05-24
0.43%
probability
This CVE has a 0.43% probability
of being exploited in the next 30 days.
0%
Top 62.9th percentile of all CVEs
100%
CVSS score unavailable
Neither CIRCL nor NVD returned a CVSS score for this CVE.
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Attack Intelligence
Google fixes second actively exploited Chrome zero-day bug this year
BleepingComputer
Mar 02, 2021
Microsoft March 2021 Patch Tuesday fixes 82 flaws, 2 zero-days
BleepingComputer
Mar 09, 2021
Signal Intelligence
Confidence
85%
EPSS
0.43%
Mentions
2
Last Seen
Mar 09, 2021
CNA Information
Analyst Note
Article [1] explicitly names this CVE as an 'actively exploited Chrome zero-day bug' fixed by Google in 2021, with clear language matching zero-day criteria. Article [2] mentions Microsoft Patch Tuesday fixing zero-days, but the critical evidence comes from [1]'s direct attribution of active exploitation to this specific CVE before/concurrent with the patch.
Triage Info
Decided atMar 20, 2026