National CERT has issued a critical alert for a Google Chrome zero-day flaw that allows remote code execution, urging users and organisations to update to the latest December 2025 version immediately.
Critical Chrome Flaw Under Active Exploitation
The National Computer Emergency Response Team (NCERT) has issued a high-priority security advisory about a critical zero-day vulnerability in Google Chrome that is already being exploited in the wild. According to the advisory, the flaw could allow attackers to gain control of affected systems with little or no user interaction.
NCERT has warned that the vulnerability affects all desktop versions of Google Chrome, including Windows, macOS and Linux. The exploit can be triggered simply by visiting a malicious or compromised website, meaning users can be targeted during normal browsing activity without clicking on suspicious links or downloading files.
Remote Code Execution and Full System Compromise
The advisory notes that the vulnerability enables remote code execution (RCE), which allows attackers to run arbitrary code on a victim’s machine. In practice, this means that once a user visits a compromised page, an attacker could potentially bypass Chrome’s built-in security protections and execute malicious instructions in the background.
If successfully exploited, the flaw may lead to full system compromise. Possible consequences include data theft, unauthorised access to sensitive information, and control over system settings. NCERT has warned that attackers could steal stored browser data and credentials, install malware, add backdoors for future access and change critical configuration files without the user’s knowledge.
The vulnerability has been rated critical with a CVSS score of 9.8, placing it among the most serious categories of security flaws. Such a high score reflects both the ease of exploitation and the potential damage to affected systems.
Who Is Affected and Signs of Possible Compromise
NCERT has stated that all Chrome desktop users running versions released before the December 2025 stable update are at risk. The advisory also warns that other Chromium-based browsers, such as Microsoft Edge, Brave and Opera, may be affected if they rely on the same vulnerable engine and have not yet been updated.
Users and administrators are being advised to watch for indicators of compromise that could suggest an active attack. Warning signs include unusual Chrome background processes, sudden spikes in CPU or memory usage while browsing, unexpected network activity after visiting websites, and the appearance of unknown or suspicious files on the system.
While these signs do not confirm an attack on their own, they should prompt users to investigate further, run updated antivirus or endpoint protection scans and review recent browsing history for potentially unsafe sites.
Immediate Updates Strongly Recommended
In its advisory, NCERT has strongly urged all users and organisations to update Google Chrome to the latest December 2025 stable release as soon as possible. Simply closing and reopening the browser may not be enough; users should check the version number in Chrome’s settings and ensure that the update has been fully installed.
After updating, users are advised to restart the browser so that the security fix is properly applied. Organisations have been told to roll out the update across all managed systems without delay, using centralised update tools where available to avoid leaving any devices unpatched.
Additional Steps for Organisations and Power Users
Beyond applying the immediate patch, NCERT has recommended a series of additional measures to reduce the risk of exploitation. These include closely monitoring browser and network activity for anomalies, limiting unnecessary browser extensions, and enforcing strict policies on which sites and scripts are allowed to run within corporate environments.
Organisations are also encouraged to strengthen endpoint and network security by updating antivirus solutions, enabling intrusion detection and prevention systems, and reviewing web proxy and firewall rules. Regular security awareness training can help users recognise suspicious behaviour, even when attacks attempt to exploit browser flaws silently.
For individual users, best practices include keeping the operating system and all applications updated, avoiding untrusted websites, regularly backing up important data and using reputable security tools. While the latest Chrome update addresses this specific zero-day, staying secure over the long term requires a combination of timely patching and cautious browsing habits.
