8.8

CVE-2021-21220: Google Chromium V8 Improper Input Validation Vulnerability

KEV
Analyzed
AliasesUBUNTU-CVE-2021-21220DEBIAN-CVE-2021-21220ALPINE-CVE-2021-21220
Published 26-04-2021Last modified 21-10-2025

Vulnerability summary

CVE-2021-21220 is a high (CVSS 8.8) Out-of-bounds Write vulnerability in Google Chromium V8. It is known to be exploited: CISA lists it, first on 03-11-2021. EPSS estimates a 70.44% chance of exploitation in the next 30 days, higher than 99.3% of scored vulnerabilities. 3 public exploits are recorded.

Priority
Act nowlisted as exploited

Listed as exploited by CISA (03-11-2021)

Source freshness unavailable

How is this decided?
CVSS score
8.8/10
010
High · v3.1 (CVE.org)
EPSS score
70.44%
0%100%
Critical · 0.00 pp in 30 days
KEVExploited in the wildCritical · listed in 1 catalog
RansomwareNot flaggedNo ransomware use recorded.
Public exploits3reference, metasploit

Advisory lineage

Upstream 0 · Downstream 5 · Related 5
OPENSUSE-SU-2021:0567-1OPENSUSE-SU-2021:0575-1OPENSUSE-SU-2021:0712-1OPENSUSE-SU-2024:10681-1OPENSUSE-SU-2024:12948-1

Timeline

  1. 26-04-2021
    PublishedVulnerability first disclosed.
  2. 03-11-2021
    Added to CISA KEVExploitedGoogle Chromium V8 Improper Input Validation Vulnerability
  3. 17-11-2021
    CISA remediation dueDeadline passedApply updates per vendor instructions.
  4. 21-10-2025
    Last modifiedVulnerability information updated.

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.

CVSS metrics

6 scores · 5 sources · 2 versions

EPSS trend

Probability

70.44%

Chance of exploitation in the next 30 days

Percentile

99%

Versus all other CVEs

30-day change

No change 0.00 pp

From 70.44% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEVListed
Added
03-11-2021
Federal due date
17-11-2021
ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

CISA required action

Apply updates per vendor instructions. nvd.nist.gov/vuln/detail/CVE-2021-21220

Public exploits

3 found
  • referenceUnverified

    Exploit Reference (crbug.com)

    Maturity: unknown

  • referenceUnverified

    Exploit Reference (packetstormsecurity.com)

    Maturity: unknown

  • MetasploitMetasploitremoteUnverified

    Google Chrome versions before 89.0.4389.128 V8 XOR Typer Out-Of-Bounds Access RCE

    exploit/multi/browser/chrome_cve_2021_21220_v8_insufficient_validation

    Maturity: poc

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, user interaction (CVSS vector). Other conditions: not stated in public data.

Alpine2 products
  • chromium< 89.0.4389.128-r0
  • qt5-qtwebengine< 5.15.3_git20210510-r0
Debian1 product
  • chromium< 90.0.4430.72-1
Fedoraproject1 product
Google1 product
  • chrome≥ unspecified, < 89.0.4389.128 | < 89.0.4389.128
Ubuntu1 product
  • chromium-browser< 90.0.4430.72-0ubuntu0.16.04.1 | < 90.0.4430.72-0ubuntu0.18.04.1

5 vendors · 6 products

References

14 links
Show all 14 references