CVE-2021-21220
HIGHCISA KEVEPSS 99th pctlDescription
Insufficient validation of untrusted input in V8 in Google Chrome prior to 89.0.4389.128 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.
How to fix
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Exploit Intelligence
Very high risk: more likely to be exploited than 99% of all known CVEs.
Google Chromium V8 Improper Input Validation Vulnerability
Google Chromium V8 Engine contains an improper input validation 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.
Apply updates per vendor instructions.
Remediation due: 2021-11-17
References
Related Vulnerabilities
Other CWE-787 (Out-of-bounds Write) vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2025-22457 | Critical | 9.0 | 100% | KEV + Ransom | Fix |
| CVE-2025-0282 | Critical | 9.0 | 100% | KEV + Ransom | - |
| CVE-2015-3113 | Critical | 9.8 | 100% | KEV | Fix |
| CVE-2021-20038 | Critical | 9.8 | 100% | KEV + Ransom | - |
| CVE-2023-4863 | High | 8.8 | 100% | KEV | Fix |
| CVE-2020-16040 | Medium | 6.5 | 100% | - | Fix |
Common questions
How do I fix CVE-2021-21220?
Published advisories record a fix for 8 affected products. The "How to fix" section on this page lists the fixed version and source advisory for each one, so apply the entry matching what you actually run.
Is CVE-2021-21220 being actively exploited?
Yes. CVE-2021-21220 is listed in the CISA Known Exploited Vulnerabilities catalog, which means exploitation has been observed in the wild. US federal agencies were required to remediate it by 2021-11-17. Treat it as a priority whatever its CVSS score says.
How severe is CVE-2021-21220?
CVE-2021-21220 has a CVSS v3 base score of 8.8, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2021-21220 affect?
Published advisories record a fix for chromium (Debian), Google Chrome (Windows application), Google Chrome (EXE) (Windows application), Google Chrome Beta (Windows application), and 4 more. Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
Embed a live status badge for CVE-2021-21220
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-10-24.