CVE-2026-9968: Integer overflow in V8 in Google Chrome prior to 148

Synopsis

An integer overflow in V8, the JavaScript engine embedded in Google Chrome, allows a remote attacker to execute arbitrary code inside the browser sandbox by luring a user to a crafted HTML page. The vulnerability is reachable over the network with no authentication required, but does require the victim to visit a malicious or attacker-controlled page. Successful exploitation gives the attacker code execution within the Chrome sandbox, which can serve as a stepping stone to further compromise. A patched-image rebuild at version 148.0.7778.216 is available on HarborGuard for environments running an affected version of Chrome.

HarborGuard Coverage

Exploit Conditions

• Network reachabilityRequired

  The attacker delivers the exploit over the network; the target Chrome instance must be able to reach and render an attacker-controlled HTML page.

• AuthenticationNot required

  No account or credential is needed; the attacker only needs the victim to load a page.

• Victim interactionRequired

  The victim must navigate to or be redirected to a crafted HTML page, making this a social-engineering or malicious-ad delivery scenario.

• Attack complexityDetail

  Attack complexity is Low, meaning the exploit is reliable and does not depend on race conditions, specific memory layouts, or other environmental factors outside the attacker's control.

Blast Radius

• The attacker executes arbitrary code inside the Chrome renderer sandbox, gaining full control of script execution within that process.
• Confidential data accessible to the browser process, such as session cookies, stored credentials, and page content, is exposed to the attacker.
• The attacker can modify in-page data and interact with web services authenticated by the victim's session, tampering with requests and responses.
• Sandbox escape is not guaranteed by this CVE alone, but code execution inside the renderer is a recognized first stage toward full host compromise via a chained exploit.