CVE-2026-87608Network attack vector

Origin-policy bypass via improper FedCM certificate validation

Published Sep 9, 2026 · Updated Sep 9, 2026

A certificate validation error in FedCM in Google Chrome before 153.0.8010.36 allows remote attackers to bypass web origin policy via crafted traffic. The Chromium issue remains restricted, so Google has not disclosed which FedCM certificate property or validation path is handled incorrectly. Exploitation requires social engineering; the documented consequence is limited to bypass of the browser's web-origin boundary.

CVSS severity6.5
Medium
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

A certificate validation error in FedCM in Google Chrome before 153.0.8010.36 allows remote attackers to bypass web origin policy via crafted traffic. The Chromium issue remains restricted, so Google has not disclosed which FedCM certificate property or validation path is handled incorrectly. Exploitation requires social engineering; the documented consequence is limited to bypass of the browser's web-origin boundary.

The record

CVE
CVE-2026-87608
Published
Sep 9, 2026
Updated
Sep 9, 2026
Vendor
Google Cloud
Product
Google Chrome
Classifications
CWE-295
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

Compare your product and version with the public record. A matching version still requires validation against your environment.

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

5.8TenableAV:N/AC:M/Au:N/C:P/I:P/A:N
6.5TenableCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-295Improper Certificate Validation

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo