How severe is CVE-2021-21193?

CVE-2021-21193 has a CVSS 3.1 base score of 8.8 (HIGH). EPSS estimates a 9.9% probability of exploitation in the next 30 days. It is listed in the CISA Known Exploited Vulnerabilities catalog.

CVE-2021-21193: Google Chromium Blink Use-After-Free Vulnerability

CISA Known Exploited Vulnerabilities

Google Chromium Blink Use-After-Free Vulnerability is confirmed as actively exploited and is listed in the CISA KEV catalog.

Added to KEV

2021-11-03

Remediation due

2021-11-17

Required action
Apply updates per vendor instructions.

CISA notes
https://nvd.nist.gov/vuln/detail/CVE-2021-21193

Description

Use after free in Blink in Google Chrome prior to 89.0.4389.90 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.

Severity

CVSS 3.1 · CISA8.8 HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

SSVC · CISA-ADP

Exploitationactive

Automatableno

Technical impacttotal

Exploitation Context

as of October 15, 2026

All KEV statistics→

CISA added CVE-2021-21193 to the KEV catalog 232 days after its CVE record was published.
It is one of 75 Google entries in the CISA KEV catalog, and one of 23 added in 2021.
Its current EPSS score (9.9%) is higher than that of 25% of CISA KEV entries.

Affected Products

Vendor	Product	Affected versions
Google	Google Chrome	unspecified to <89.0.4389.90

References

5 Links

Vendor advisories

Other references

Record Details

Published

2021-03-16

Last updated

2025-10-21

Assigner (CNA)

Chrome

Credited to

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CVE record data © The MITRE Corporation, used under the CVE Terms of Use. Exploited-in-the-wild data from the CISA Known Exploited Vulnerabilities catalog (CC0). Exploit prediction scores by FIRST EPSS (first.org/epss). This site is not endorsed or certified by MITRE, NVD, CISA, or FIRST.