CVE-2026-17977Network attack vector

Cross-origin data disclosure via CSS policy bypass

Published Jul 30, 2026 · Updated Jul 30, 2026

Policy bypass in CSS in Google Chrome before 151.0.7922.72 allows remote attackers to read cross-origin data via a crafted HTML page. Google has not disclosed the CSS processing locus or the incorrect origin-policy operation; the linked Chromium issue remains restricted. A user must open attacker-controlled HTML, after which the page can disclose cross-origin data without modifying content or interrupting the browser.

CVSS severity4.3
Medium
EPSS probability0.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Policy bypass in CSS in Google Chrome before 151.0.7922.72 allows remote attackers to read cross-origin data via a crafted HTML page. Google has not disclosed the CSS processing locus or the incorrect origin-policy operation; the linked Chromium issue remains restricted. A user must open attacker-controlled HTML, after which the page can disclose cross-origin data without modifying content or interrupting the browser.

The record

CVE
CVE-2026-17977
Published
Jul 30, 2026
Updated
Jul 30, 2026
Vendor
Go standard library
Product
Google Chrome
Classifications
CWE-346, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 30, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 30, 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=151.0.7922.72 <151.0.7922.72

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Go standard library · Google Chromeversion=151.0.7922.72 <151.0.7922.72

Published CVSS scores

4.3CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/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-346Origin Validation Error
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.

Technologies

Your stack

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Your stack

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