CVE-2026-7337Public exploitNetwork attack vector

Sandboxed code execution via elided Smi check

Published Apr 28, 2026 · Updated Apr 28, 2026

Type confusion in V8 Maglev in Google Chrome before 147.0.7727.138 allows remote attackers to execute code in the sandbox via crafted HTML. MaglevGraphBuilder::BuildCheckSmi treats a range-compatible tagged HeapNumber as an Smi and removes its tag check and write barrier. A user must load attacker-controlled HTML; the published exploit achieves native renderer-process execution but does not itself escape the Chrome sandbox.

CVSS severity8.8
High
EPSS probability0.42%
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 Maglev in Google Chrome before 147.0.7727.138 allows remote attackers to execute code in the sandbox via crafted HTML. MaglevGraphBuilder::BuildCheckSmi treats a range-compatible tagged HeapNumber as an Smi and removes its tag check and write barrier. A user must load attacker-controlled HTML; the published exploit achieves native renderer-process execution but does not itself escape the Chrome sandbox.

The record

CVE
CVE-2026-7337
Published
Apr 28, 2026
Updated
Apr 28, 2026
Vendor
Go standard library
Product
Google Chrome
Classifications
CWE-843, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 28, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 28, 2026Record 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=147.0.7727.138 <147.0.7727.138

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Go standard library · Google Chromeversion=147.0.7727.138 <147.0.7727.138

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.

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 exploitPublished

Weakness, pattern, technique

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

Public exploit references

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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