CVE-2026-78949

Cross-origin data disclosure via CustomTabs discrepancy

Published Aug 25, 2026 · Updated Aug 25, 2026

Observable discrepancy in Google Chrome CustomTabs before 152.0.7977.65 allows local users to obtain cross-origin data on Android. Google has not published which CustomTabs state or response differs, or how the co-installed app observes that difference to cross the origin boundary. Exploitation requires an app installed on the same Android device and user interaction; the reported consequence is disclosure of cross-origin data, with no integrity or availability impact.

CVSS severity5.5
Medium
EPSS probability0.10%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Observable discrepancy in Google Chrome CustomTabs before 152.0.7977.65 allows local users to obtain cross-origin data on Android. Google has not published which CustomTabs state or response differs, or how the co-installed app observes that difference to cross the origin boundary. Exploitation requires an app installed on the same Android device and user interaction; the reported consequence is disclosure of cross-origin data, with no integrity or availability impact.

The record

CVE
CVE-2026-78949
Published
Aug 25, 2026
Updated
Aug 25, 2026
Vendor
Google Cloud
Product
Google Chrome
Classifications
CWE-203
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Aug 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 25, 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=152.0.7977.65 <152.0.7977.65

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

Google Cloud · Google Chromeversion=152.0.7977.65 <152.0.7977.65

Published CVSS scores

1.9TenableAV:L/AC:M/Au:N/C:P/I:N/A:N
5.5TenableCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/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)
Vectorlocal
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-203Observable Discrepancy

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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