CVE-2026-11660: Insufficient validation of untrusted input in New Tab Page in Google Chrome prior to 149

Synopsis

Insufficient input validation in the New Tab Page component of Google Chrome (versions prior to 149.0.7827.103) allows a remote attacker who has already compromised the renderer process to escape the browser sandbox via a specially crafted HTML page. The attack is reachable over the network, requires no authentication, but does need the victim to interact with a crafted page, and exploitation is conditional on first having a renderer compromise in place. Successful exploitation gives the attacker full read, write, and crash capability outside the sandbox, effectively achieving code execution at the host level. A patched-image rebuild at version 149.0.7827.103 is available on HarborGuard for affected environments.

HarborGuard Coverage

Exploit Conditions

• Network reachabilityRequired

  The attacker delivers the crafted HTML page over the network, so the targeted Chrome instance must be reachable or the user must browse to an attacker-controlled origin.

• AuthenticationNot required

  No account or credential is needed; the attack is launched from an unauthenticated web context.

• Victim interactionRequired

  The victim must visit or be redirected to the attacker-crafted HTML page, making social engineering or malicious ad delivery a prerequisite.

• Attack complexityDetail

  Exploitation is rated AC:H, meaning the attacker must first have achieved renderer-process compromise before this sandbox escape becomes possible, introducing a significant prerequisite beyond simple delivery.

Blast Radius

• Reads sensitive data from processes and memory regions outside the Chrome sandbox, including credentials, session tokens, and files accessible to the browser process user.
• Writes or modifies files and system state outside the sandbox, enabling persistence mechanisms or tampering with local data.
• Crashes or destabilizes processes outside the renderer, potentially taking down the entire browser or dependent host services.
• Achieves arbitrary code execution at the privilege level of the host process, bypassing Chrome's primary security boundary entirely.