CVE-2021-21220
KEVGoogle Chromium V8 Improper Input Validation Vulnerability
Description
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.
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.
CVSS 3.1 vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HPublishedApr 26, 2021
Last modifiedJun 17, 2026
Added to KEVNov 3, 2021
Remediation dueNov 17, 2021
References
- packetstormsecurity.com/files/162437/Google-Chrome-XOR-Typer-Out-Of-Bounds-Access-Remote-Code-Execution.htmlExploitThird Party Advisory
- packetstormsecurity.com/files/176210/Chrome-V8-JIT-XOR-Arbitrary-Code-Execution.htmlThird Party AdvisoryVDB Entry
- chromereleases.googleblog.com/2021/04/stable-channel-update-for-desktop.htmlRelease Notes
- crbug.com/1196683ExploitIssue Tracking
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EAJ42L4JFPBJATCZ7MOZQTUDGV4OEHHG/Release Notes
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/U3GZ42MYPGD35V652ZPVPYYS7A7LVXVY/Release Notes
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VUZBGKGVZADNA3I24NVG7HAYYUTOSN5A/Release Notes
- security.gentoo.org/glsa/202104-08Third Party Advisory
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-21220US Government Resource
0 recent articles mention this CVE
81
Risk assessment · Critical
Actively exploited. Patch immediately.
- Exploitation
- Confirmed in the wild (CISA KEV)
- Federal remediation deadline
- Overdue by 1804 days
- CVSS
- 8.8 HIGH
- EPSS (30-day exploit probability)
- 70.4% · top 1% of all CVEs
- Weakness
- CWE-787
- Attack vector
- Network, remotely reachable
Recommended actions
- 1.Apply updates per vendor instructions.
- 2.Treat as emergency change: patch or isolate internet-facing instances first.
- 3.Review exposure: confirm which instances are reachable from the internet and restrict access until patched.
- 4.Hunt for compromise: review logs for the disclosure window, not just from the patch date.
Assessment is derived automatically from the live signals above; verify against your own asset inventory.