CVE-2021-21223
✓ Confirmed 0-Day
Triaged: March 20, 2026
1 article
EPSS Score
Source: FIRST.org · 2026-05-24
1.16%
probability
This CVE has a 1.16% probability
of being exploited in the next 30 days.
0%
Top 78.8th percentile of all CVEs
100%
CVSS score unavailable
Neither CIRCL nor NVD returned a CVSS score for this CVE.
View on VulnerabilityLookup ↗
Google fixes exploited Chrome zero-day dropped on Twitter last week
BleepingComputer
Apr 21, 2021
Signal Intelligence
Confidence
85%
EPSS
1.16%
Mentions
1
Last Seen
Apr 21, 2021
CNA Information
Analyst Note
BleepingComputer article explicitly identifies CVE-2021-21223 as an 'exploited Chrome zero-day' with active exploitation occurring before patch availability (exploit 'dropped on Twitter last week' prior to Google's fix). CVE year 2021 and contemporary reporting align with zero-day exploitation criteria.
Triage Info
Decided atMar 20, 2026