CVE-2021-38003Known exploitationNetwork attack vector

Heap corruption via V8 implementation flaw

Published Nov 23, 2021 · Updated Oct 21, 2025

Google Chrome before 95.0.4638.69 contains an inappropriate V8 implementation that lets remote attackers corrupt heap memory through crafted HTML. The flaw is in V8's handling of crafted page data, where an incorrect implementation permits heap corruption during browser processing. Exploitation requires a remote attacker to deliver a malicious page and a user to load it; Google reports exploits in the wild, with potential compromise of confidentiality, integrity, and availability.

CVSS severity8.8
High
EPSS probability38.57%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Google Chrome before 95.0.4638.69 contains an inappropriate V8 implementation that lets remote attackers corrupt heap memory through crafted HTML. The flaw is in V8's handling of crafted page data, where an incorrect implementation permits heap corruption during browser processing. Exploitation requires a remote attacker to deliver a malicious page and a user to load it; Google reports exploits in the wild, with potential compromise of confidentiality, integrity, and availability.

The record

CVE
CVE-2021-38003
Published
Nov 23, 2021
Updated
Oct 21, 2025
Vendor
Google Cloud
Product
Google Chrome
Classifications
T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 28, 2021Exploitation reportedGoogle reports exploitation in the wild
  2. Nov 3, 2021Exploitation reportedCISA Known Exploited Vulnerabilities listing
  3. Nov 23, 2021CVE publishedPublication date reported by the CVE source.
  4. Oct 21, 2025Record 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 <95.0.4638.69

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Google Cloud · Google Chromeversion=unspecified <95.0.4638.69

Published CVSS scores

8.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationReported
Public exploitUnconfirmed

Weakness, pattern, technique

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.

Reported exploitation

Technologies

Your stack

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Your stack

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