Critical Chromium Browser Vulnerability Under Active Exploit
A zero-day vulnerability in Chromium-based browsers is now being actively exploited and it poses a serious risk to users across industries, including defense and government contractors. The flaw, CVE-2025-6554, allows attackers to execute malicious code simply by luring a user to a compromised website. That’s right. No clicks, no downloads. All it takes is visiting the wrong webpage.
WHO’S AT RISK
Anyone using a Chromium-based browser — which includes most major browsers — is vulnerable. For cleared contractors and organizations handling sensitive information, this kind of “drive-by” exploit can lead to system compromise, data exfiltration, and downstream risks to national security.
Affected browsers include:
- Google Chrome
- Microsoft Edge
- Brave
- Opera
- Any Chromium-based browser on Windows, macOS, or Linux
Not affected (but still recommended to update):
- Mozilla Firefox
- Apple Safari
HOW THEY’RE ATTACKING
This exploit is dangerously simple. There’s no phishing email and no file downloading. If your browser is unpatched and you land on a malicious or compromised site, the exploit can trigger instantly.
That makes it an ideal tool for:
- Espionage campaigns
- Credential harvesting
- Malware installation
- Stealth surveillance
WHAT TO DO NOW
Update Your Browser Immediately
- Chrome: Go to ⋮ > Help > About Google Chrome → It will auto-update. Relaunch when prompted.
- Edge: Go to ... > Help and Feedback > About Microsoft Edge → Relaunch to apply update.
Restart Your Browser
- Updates won’t take effect until the browser is restarted.
Avoid Suspicious Websites
- Be extra cautious about clicking unknown links especially from emails, texts, and social media.
HOW ISI CAN HELP
We’re tracking the situation closely and standing by to assist. ISI teams can help you:
- Verify browser patch status across systems
- Provide user awareness training for your team
- Monitor for unusual activity post-patch
- Review access logs or alert settings for compromise indicators
This is an actively exploited zero-day with no user interaction required. The threat is real and immediate and so is the fix. Update your browser now and help others in your company do the same. It's the simplest, most effective way to stay safe.
