Input validation error in Google Chromium - CVE-2026-9903

Vulnerability identifier: #VU132814

CSH Severity: High

CVSS v4: 8.4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-9903

CWE-ID: CWE-20

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to improper input validation in Site Isolation component in Google Chrome. A remote attacker can trick the victim to open a specially crafted web page and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Google Chromium
Microsoft Edge
Debian Linux
Fedora
Chrome OS
chromium
chromium (Debian package)

Install update from vendor's website.

Google Chromium - update to 148.0.7778.215
Microsoft Edge - update to 148.0.3967.96
Chrome OS - update to 144.0.7559.256
chromium - addressed in versions 148.0.7778.215-1.el9, 148.0.7778.215-1.el10_2, 148.0.7778.215-1.el10_3, 148.0.7778.215-1.fc43, 148.0.7778.215-1.fc44
chromium (Debian package) - addressed in versions 148.0.7778.215-1~deb12u1, 148.0.7778.215-1~deb13u1

• https://chromereleases.googleblog.com/2026/05/stable-channel-update-for-desktop_0877304591.html
• https://crbug.com/498783665

• Multiple vulnerabilities in Google Chrome
• Fedora EPEL 9 update for chromium
• Fedora 43 update for chromium
• Fedora EPEL 10.3 update for chromium
• Fedora EPEL 10.2 update for chromium
• Fedora 44 update for chromium
• Debian update for chromium
• Multiple vulnerabilities in Microsoft Edge
• Multiple vulnerabilities in Google ChromeOS LTS