CVE-2025-6556Network attack vector

CSP bypass via Loader policy enforcement failure

Published Jun 24, 2025 · Updated Feb 26, 2026

Insufficient policy enforcement in Google Chrome's Loader before 138.0.7204.49 allows remote attackers to bypass CSP via crafted HTML. Google identifies the Loader as the faulty component but has not published which policy check is omitted or incorrectly applied to attacker-controlled content. User interaction is required to load the crafted page; published evidence establishes neither arbitrary code execution nor availability impact.

CVSS severity5.4
Medium
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Insufficient policy enforcement in Google Chrome's Loader before 138.0.7204.49 allows remote attackers to bypass CSP via crafted HTML. Google identifies the Loader as the faulty component but has not published which policy check is omitted or incorrectly applied to attacker-controlled content. User interaction is required to load the crafted page; published evidence establishes neither arbitrary code execution nor availability impact.

The record

CVE
CVE-2025-6556
Published
Jun 24, 2025
Updated
Feb 26, 2026
Vendor
Google Cloud
Product
Google Chrome
Classifications
CWE-288, T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 24, 2025CVE publishedPublication date reported by the CVE source.
  2. Feb 26, 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=138.0.7204.49 <138.0.7204.49

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Google Cloud · Google Chromeversion=138.0.7204.49 <138.0.7204.49

Published CVSS scores

5.4CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/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 exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-288Authentication Bypass Using an Alternate Path or Channel
T1189Drive-by Compromise

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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