CVE intelligence

CVE-2026-78903

Vulnerability intelligence

Published Aug 25, 2026Sources checked Sep 12, 2026

3.1LOWCVSS out of 10

What this means

Review the available evidence

CVE-2026-78903 and is rated Low severity with a CVSS score of 3.1. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

CISA KEVNot listedBased on the latest collected catalog

EPSS0.3%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-78903?

Incomplete cleanup in SiteIsolation in Google Chrome prior to 152.0.7977.65 allowed a remote attacker who had compromised the renderer process to bypass site isolation via a crafted HTML page. (Chromium security severity: Medium)