CVE-2026-87561Network attack vector

Origin-policy bypass via crafted browser extension

Published Sep 9, 2026 · Updated Sep 9, 2026

Incorrect authorization in Google Chrome Web Authentication before 153.0.8010.36 allows remote attackers to bypass web origin policy. The public Chrome advisory identifies Web Authentication as the affected locus but does not disclose which authorization check mishandles extension-origin input. A crafted browser extension and user interaction are required, and the documented consequence is limited to crossing the web-origin boundary.

CVSS severity4.3
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

Incorrect authorization in Google Chrome Web Authentication before 153.0.8010.36 allows remote attackers to bypass web origin policy. The public Chrome advisory identifies Web Authentication as the affected locus but does not disclose which authorization check mishandles extension-origin input. A crafted browser extension and user interaction are required, and the documented consequence is limited to crossing the web-origin boundary.

The record

CVE
CVE-2026-87561
Published
Sep 9, 2026
Updated
Sep 9, 2026
Vendor
Google Cloud
Product
Google Chrome
Classifications
CWE-863, T1204.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 9, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 9, 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=153.0.8010.36 <153.0.8010.36

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Google Cloud · Google Chromeversion=153.0.8010.36 <153.0.8010.36

Published CVSS scores

4.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/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-863Incorrect Authorization
T1204.002User Execution: Malicious File

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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