CVE-2026-9918: Inappropriate implementation in Tint in Google Chrome prior to 148

Synopsis

An inappropriate implementation flaw in the Tint rendering component of Google Chrome prior to version 148.0.7778.216 allows a remote attacker to escape the browser sandbox by tricking a user into visiting a crafted HTML page. The vulnerability is reachable over the network, requires no authentication, but does require the victim to interact with attacker-controlled content. Successful exploitation gives the attacker full read, write, and availability impact on the affected system, breaking out of the browser sandbox entirely. 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 must reach the victim over the network, delivering a crafted HTML page via a browser-accessible URL.

• AuthenticationNot required

  No account or credential is needed; any unauthenticated remote attacker can attempt the exploit.

• Victim interactionRequired

  The victim must visit or be redirected to an attacker-controlled HTML page, making social engineering or malicious ad delivery the likely delivery vector.

• Attack complexityDetail

  Attack complexity is Low, meaning the exploit is reliable and requires no special timing, race conditions, or environmental prerequisites beyond victim interaction.

Blast Radius

• A successful attacker escapes the Chrome browser sandbox, gaining code execution outside the browser process boundary.
• With sandbox escape achieved, the attacker can read files and data accessible to the user running Chrome, including stored credentials and session tokens.
• The attacker can write or modify files on the host system under the permissions of the compromised user account.
• The attacker can disrupt or crash host-level processes accessible to that user, affecting availability beyond the browser itself.