CVE Watch—

CVE-2021-21166

Google Chromium Race Condition Vulnerability

CVSS

—

No CVSS

EPSS

24.0%

p98

KEV

YES

Nov 3, 2021

Exploit Today

0-100

Published: — · Last modified: —

EPSS · 30d

24.0%EPSS · 30 days26.7%

2026-09-182026-10-16

KEV catalog record

Product

Google / Chromium

Vulnerability

Google Chromium Race Condition Vulnerability

Added to KEV

Nov 3, 2021

Remediate by

Nov 17, 2021

Known ransomware use

Summary description

Google Chromium contains a race condition vulnerability that allows a remote attacker to potentially exploit heap corruption via a crafted HTML page. This vulnerability could affect multiple web browsers that utilize Chromium, including, but not limited to, Google Chrome, Microsoft Edge, and Opera.

Required action

Apply updates per vendor instructions.

Notes

https://nvd.nist.gov/vuln/detail/CVE-2021-21166

Related CVEs

CVECVSSEPSSKEVRExploitTitleMod.

CVE-2025-141748.8 HIG

97.7%

KEV—79Google Chromium Out of Bounds Memory Access Vulnerability9d CVE-2025-65588.8 HIG

95.8%

KEV—79Google Chromium ANGLE and GPU Improper Input Validation Vulnerability16d CVE-2026-2441—

99.0%

KEV—80Google Chromium CSS Use-After-Free Vulnerability—CVE-2021-37976—

97.4%

KEV—79Google Chromium Information Disclosure Vulnerability—CVE-2024-4671—

94.9%

KEV—78Google Chromium Visuals Use-After-Free Vulnerability—