CVE-2026-3063 is a vulnerability identified in Google Chrome's DevTools implementation prior to version 145.0.7632.116. The flaw arises from an inappropriate implementation that allows malicious extensions to inject arbitrary scripts or HTML into privileged pages accessed via DevTools. This occurs when an attacker convinces a user to install a crafted malicious extension, which then leverages DevTools to perform script or HTML injection. Such injection can lead to unauthorized code execution within the browser, potentially compromising browser security, user data confidentiality, and integrity of privileged browser pages. The vulnerability does not require the attacker to have authentication beyond the user installing the extension, but it does require user interaction to install the malicious extension. The lack of a CVSS score suggests this is a newly disclosed issue, but the Chromium security team has rated it as High severity, indicating significant risk. No known exploits have been reported in the wild yet, but the potential for exploitation exists given the widespread use of Chrome and the common practice of installing extensions. The vulnerability affects all Chrome users running versions prior to 145.0.7632.116, which is a recent release, emphasizing the need for immediate patching. The threat is particularly relevant for environments where users have the ability to install extensions without administrative oversight, such as enterprise or educational settings.

The potential impact of CVE-2026-3063 is substantial for organizations worldwide. Successful exploitation can lead to unauthorized code execution within the browser context, enabling attackers to manipulate privileged pages, steal sensitive information, or alter browser behavior. This compromises confidentiality and integrity of user data and browser sessions. In enterprise environments, this could facilitate lateral movement or data exfiltration if attackers gain foothold through compromised browsers. The requirement for user interaction (installing a malicious extension) limits the ease of exploitation but does not eliminate risk, especially in environments with less strict extension policies or where social engineering is effective. The vulnerability could also be leveraged as a stepping stone for more complex attacks targeting internal networks or cloud services accessed via Chrome. Given Chrome's dominant market share globally, the scope of affected systems is vast, increasing the potential scale of impact.

To mitigate CVE-2026-3063, organizations and users should immediately update Google Chrome to version 145.0.7632.116 or later, where the vulnerability is patched. Administrators should enforce strict extension installation policies, limiting installations to verified and trusted sources such as the official Chrome Web Store and employing enterprise policies to whitelist approved extensions. Regular audits of installed extensions should be conducted to detect and remove any unauthorized or suspicious add-ons. User education is critical to reduce the risk of social engineering attacks that trick users into installing malicious extensions. Additionally, organizations can deploy endpoint protection solutions that monitor browser behavior and detect anomalous activities related to DevTools or extension misuse. For high-security environments, consider disabling or restricting DevTools access where feasible. Monitoring browser logs and network traffic for unusual patterns may also help detect exploitation attempts early.