CVE-2021-21220

Name: CVE-2021-21220
Creator: NVD / NIST
Published: 2021-04-26T17:15:08.593+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.8/10Actively ExploitedEPSS 70.44%

Last modified Jun 17, 2026

CVE-2021-21220 is a high-severity vulnerability rated 8.8/10 on the CVSS scale. 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.. CISA has confirmed active exploitation in the wild. EPSS estimates a 70.44% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1

8.8/10

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

EPSS Probability

70.44%

99.3th percentile

Probability of exploitation in the next 30 days. Learn more

Exploitation Status

This vulnerability is listed in CISA’s Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. Federal agencies must remediate by Nov 17, 2021.

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Google	Chrome	< 89.0.4389.128
Fedoraproject	Fedora	32
Fedoraproject	Fedora	33
Fedoraproject	Fedora	34

References

http://packetstormsecurity.com/files/162437/Google-Chrome-XOR-Typer-Out-Of-Bounds-Access-Remote-Code-Execution.htmlExploit, Third Party Advisory, VDB Entry
http://packetstormsecurity.com/files/176210/Chrome-V8-JIT-XOR-Arbitrary-Code-Execution.htmlThird Party Advisory, VDB Entry
https://chromereleases.googleblog.com/2021/04/stable-channel-update-for-desktop.htmlRelease Notes
https://crbug.com/1196683Exploit, Issue Tracking
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EAJ42L4JFPBJATCZ7MOZQTUDGV4OEHHG/Release Notes
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/U3GZ42MYPGD35V652ZPVPYYS7A7LVXVY/Release Notes
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VUZBGKGVZADNA3I24NVG7HAYYUTOSN5A/Release Notes
https://security.gentoo.org/glsa/202104-08Third Party Advisory
http://packetstormsecurity.com/files/162437/Google-Chrome-XOR-Typer-Out-Of-Bounds-Access-Remote-Code-Execution.htmlExploit, Third Party Advisory, VDB Entry
http://packetstormsecurity.com/files/176210/Chrome-V8-JIT-XOR-Arbitrary-Code-Execution.htmlThird Party Advisory, VDB Entry
https://chromereleases.googleblog.com/2021/04/stable-channel-update-for-desktop.htmlRelease Notes
https://crbug.com/1196683Exploit, Issue Tracking
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EAJ42L4JFPBJATCZ7MOZQTUDGV4OEHHG/Release Notes
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/U3GZ42MYPGD35V652ZPVPYYS7A7LVXVY/Release Notes
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VUZBGKGVZADNA3I24NVG7HAYYUTOSN5A/Release Notes
https://security.gentoo.org/glsa/202104-08Third Party Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-21220US Government Resource

Timeline

Published: Apr 26, 2021
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2021-21220?

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 severe is CVE-2021-21220?

CVE-2021-21220 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 70.44% probability of exploitation in the next 30 days. This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog.

How do I fix CVE-2021-21220?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-21220?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST