CVE-2021-21166: Google Chromium Race Condition Vulnerability
CVSS: 8.8v3.1HighKEVAnalyzed
AliasesUBUNTU-CVE-2021-21166DEBIAN-CVE-2021-21166
Published 09-03-2021Last modified 21-10-2025
Vulnerability summary
CVE-2021-21166 is a high (CVSS 8.8) Race Condition vulnerability in Google Chromium. It is known to be exploited: CISA lists it, first on 03-11-2021. EPSS estimates a 24.03% chance of exploitation in the next 30 days, higher than 97.8% of scored vulnerabilities.
CVSS score
8.8/10
010
High · v3.1 (CVE.org)EPSS score
24.03%
0%100%
High · -2.70 pp in 30 daysKEVListedCISA
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 6 · Related 4Timeline
- 09-03-2021PublishedVulnerability first disclosed.
- 03-11-2021Added to CISA KEVGoogle Chromium Race Condition Vulnerability
- 17-11-2021CISA remediation dueApply updates per vendor instructions.
- 21-10-2025Last modifiedVulnerability information updated.
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.
CVSS metrics
5 scores · 4 sources · 2 versionsHigh 8.8Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HSourcesAll 4 agree
- OSV · UbuntuEcosystem advisory · calculated8.8HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated8.8HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- NVDNIST8.8HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Medium 6.8Preferred score · NVD (NIST)
AV:N/AC:M/Au:N/C:P/I:P/A:PSourcesSingle source
EPSS trend
Probability
24.03%
Chance of exploitation in the next 30 days
Percentile
98%
Versus all other CVEs
30-day change
-2.70 pp
From 26.72% on 20-09-2026
20-09-202620-10-2026
EPSS score24.03%
Known exploited
Compare KEV catalogs
CISA KEVListed- Added
- 03-11-2021
- Federal due date
- 17-11-2021
CISA required action
Apply updates per vendor instructions. nvd.nist.gov/vuln/detail/CVE-2021-21166
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Debian2 products
- chromium< 89.0.4389.82-1
- debian_linuxEOL10.0
Fedoraproject1 product
- fedoraEOL32 | 33 | 34
Google1 product
- chrome≥ unspecified, < 89.0.4389.72 | < 89.0.4389.72
Ubuntu1 product
- chromium-browser< 89.0.4389.82-0ubuntu0.16.04.1 | < 89.0.4389.82-0ubuntu0.18.04.1
4 vendors · 5 products
References
12 links- chromereleases.googleblog.com/2021/03/stable-channel-update-for-desktop.htmlX Refsource MISCRelease Notes
www.debian.org/security/2021/dsa-4886Vendor AdvisoryX Refsource DEBIANMailing ListThird Party Advisory- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-21166Government ResourceUS Government Resource