CVE-2026-9903: Google Chrome

Medium severity, CVSS 5.0. EPSS: 0.2% chance of exploitation in the next 30 days.

Insufficient validation of untrusted input in Site Isolation in Google Chrome prior to 148.0.7778.216 allowed a remote attacker who had compromised the renderer process to bypass site isolation via a crafted MHTML page. (Chromium security severity: High)

Affected products

• Google Chrome: before 148.0.7778.216 (fixed in 148.0.7778.216)

Published 2026-05-28. Last modified 2026-07-21.