CVE-2021-4078Network attack vector

Heap corruption via V8 type confusion

Published Dec 23, 2021 · Updated Aug 3, 2024

Type confusion in V8 in Google Chrome before 96.0.4664.93 allows remote attackers to corrupt heap memory via a crafted HTML page. Google's public advisory identifies the V8 engine and type-confusion operation but keeps the underlying bug report restricted, so the faulty code path and mismatched types are undisclosed. Exploitation requires a user to load attacker-controlled HTML; the documented consequence is heap corruption, while further code-execution behavior is not publicly established.

CVSS severity8.8
High
EPSS probability0.96%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Type confusion in V8 in Google Chrome before 96.0.4664.93 allows remote attackers to corrupt heap memory via a crafted HTML page. Google's public advisory identifies the V8 engine and type-confusion operation but keeps the underlying bug report restricted, so the faulty code path and mismatched types are undisclosed. Exploitation requires a user to load attacker-controlled HTML; the documented consequence is heap corruption, while further code-execution behavior is not publicly established.

The record

CVE
CVE-2021-4078
Published
Dec 23, 2021
Updated
Aug 3, 2024
Vendor
Google Cloud
Product
Google Chrome
Classifications
CWE-843, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 23, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <96.0.4664.93

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Google Cloud · Google Chromeversion=unspecified <96.0.4664.93

Published CVSS scores

8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
6.8NIST NVDAV:N/AC:M/Au:N/C:P/I:P/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-843Access of Resource Using Incompatible Type ('Type Confusion')
T1203Exploitation for Client Execution

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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