CVE-2021-37975Known exploitationPublic exploitNetwork attack vector

Renderer code execution via premature object collection

Published Oct 8, 2021 · Updated Oct 21, 2025

Use-after-free in V8 in Google Chrome before 94.0.4606.71 allows remote attackers to execute code in the renderer via crafted HTML. V8's ephemeron-marking logic can leave reachable JavaScript objects unmarked, so garbage collection frees objects that script can still reference. Exploitation requires a user to load attacker-controlled HTML; resulting code execution starts inside Chrome's renderer sandbox.

CVSS severity8.8
High
EPSS probability34.89%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in V8 in Google Chrome before 94.0.4606.71 allows remote attackers to execute code in the renderer via crafted HTML. V8's ephemeron-marking logic can leave reachable JavaScript objects unmarked, so garbage collection frees objects that script can still reference. Exploitation requires a user to load attacker-controlled HTML; resulting code execution starts inside Chrome's renderer sandbox.

The record

CVE
CVE-2021-37975
Published
Oct 8, 2021
Updated
Oct 21, 2025
Vendor
Google Cloud
Product
Google Chrome
Classifications
CWE-416, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 8, 2021CVE publishedPublication date reported by the CVE source.
  2. Nov 3, 2021Exploitation reportedCISA Known Exploited Vulnerabilities listing
  3. 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 <94.0.4606.71

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Google Cloud · Google Chromeversion=unspecified <94.0.4606.71

Published CVSS scores

8.8CISA ADPCVSS: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.

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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 exploitationReported
Public exploitPublished

Weakness, pattern, technique

CWE-416Use After Free
T1203Exploitation for Client Execution

Public exploit references

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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