CVE-2025-6554Known exploitationNetwork attack vector

Arbitrary memory read and write via type confusion

Published Jun 30, 2025 · Updated Oct 21, 2025

Type confusion in V8 in Google Chrome before 138.0.7204.96 allows remote attackers to read and write memory via crafted HTML. Google identifies V8 as the locus but has not published the incompatible runtime types or faulty operation because bug details remain restricted. A user must load attacker-controlled HTML; successful exploitation crosses JavaScript memory-safety boundaries, and active exploitation is confirmed.

CVSS severity8.1
High
EPSS probability12.72%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Type confusion in V8 in Google Chrome before 138.0.7204.96 allows remote attackers to read and write memory via crafted HTML. Google identifies V8 as the locus but has not published the incompatible runtime types or faulty operation because bug details remain restricted. A user must load attacker-controlled HTML; successful exploitation crosses JavaScript memory-safety boundaries, and active exploitation is confirmed.

The record

CVE
CVE-2025-6554
Published
Jun 30, 2025
Updated
Oct 21, 2025
Vendor
Google Cloud
Product
Google Chrome
Classifications
CWE-843, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 30, 2025CVE publishedPublication date reported by the CVE source.
  2. Jul 2, 2025Exploitation reportedCISA Known Exploited Vulnerabilities Catalog entry
  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=138.0.7204.96 <138.0.7204.96

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Google Cloud · Google Chromeversion=138.0.7204.96 <138.0.7204.96

Published CVSS scores

8.1National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N

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 exploitationReported
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.

Reported exploitation

Technologies

Your stack

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Your stack

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