CVE-2021-21166
Google Chromium Race Condition Vulnerability
- High 8.8
- Exploited: added to CISA KEV 3 Nov 2021
Description
Data race in audio in Google Chrome prior to 89.0.4389.72 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.
Key facts
- Published
- 9 Mar 2021
- Last changed
- 21 Oct 2025
- Assigned by
- Chrome
- KEV added
- 3 Nov 2021
- KEV fix due
- 17 Nov 2021
- EPSS
- 24.027% likely to be exploited in the next 30 days, higher than 97.876% of CVEs (scores for 15 Nov 2026)
- SSVC (CISA)
- Exploitation: active; Automatable: no; Technical impact: total
Severity scores
Each score is shown as its source gave it. They are not averaged or merged.
- 8.8CVSS 3.1, Highfrom CISA (ADP container)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
What to do
- Apply updates per vendor instructions.CISA KEV required action
Historical context and remediation
This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.
No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.
Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.
Affected products
| Vendor | Product | Versions |
|---|---|---|
| Chrome |
|
Timeline
- 9 Mar 2021 Published
- 3 Nov 2021 CVE-2021-21166 added to CISA KEV
- 3 Nov 2021 Added to the CISA KEV catalogue