Chrome 155 Security Update Fixes 247 Bugs, 4 Critical: Update and Relaunch Now

The Chrome 155 security update is out, and it fixes 247 security bugs, four of them rated Critical. If Chrome hasn’t restarted since last week, you probably haven’t got it yet. Open the menu, check for updates, and relaunch.

Here are the numbers that matter before you go any further.

• Version: 155.0.8059.39/.40 on Windows and Mac, 155.0.8059.39 on Linux
• Fixes: 247 in total, including 4 Critical and 53 High severity
• Exploited in the wild: not reported, according to eSecurityPlanet
• Released: the week of October 6, 2026
• Android: rolling out gradually, starting with a small share of users

None of this needs a tech degree. It needs about thirty seconds and a browser restart.

What the Chrome 155 security update actually fixes

All four Critical bugs are use-after-free flaws. That’s a memory mistake where a program keeps using data after it has freed it, and attackers can sometimes turn that into running their own code.

The Critical bugs sit in four different parts of the browser. The table below lists them.

Per Malwarebytes, the Browser and Navigation bugs could let an attacker run code outside Chrome’s sandbox through a crafted web page. The sandbox is the wall that normally keeps a bad page away from the rest of your computer, so escaping it is the serious part.

The same report also flags a High-severity type confusion bug in V8, Chrome’s JavaScript engine. That one could allow code to run inside the sandbox.

Is it being used in attacks right now?

Not as far as anyone has said. eSecurityPlanet reports that Google hasn’t marked any of the four Critical bugs as exploited in the wild.

That’s good news, but it’s not a reason to wait. Google often limits bug details until most people have updated, and attackers study patches to work out what changed. The gap between a patch and a working exploit can be short.

How to update Chrome in under a minute

On desktop, the steps are the same on every system. Follow them in this order.

1. Click the three-dot menu in the top right corner.
2. Go to Help, then About Google Chrome.
3. Let Chrome finish downloading the update.
4. Click Relaunch, and check that the version starts with 155.

The restart is the step people skip. Until you relaunch, the old code keeps running, and the fix does nothing for you.

On Android, open the Play Store, search for Chrome, and tap Update if you see it. If you don’t, the rollout simply hasn’t reached you yet. On a Chromebook, click the update notification near the clock and restart.

What to check if you manage other people’s PCs

If you run a family computer, a small office, or a school lab, don’t assume automatic updates worked. A browser left open for weeks never installs the patch.

Check that Chrome 155 has reached every managed Windows, Mac, and Linux machine, and look for any policy that delays browser updates. The same logic applies to Chromium-based browsers like Edge, Brave, and Opera, which usually follow Chrome’s fixes within days. Updates are getting more frequent too, as we explained in our guide to the Chrome two-week release cycle.

Chrome 156 is next. It’s due on October 20, and you can see what’s coming in our Chrome 156 preview.

Frequently Asked Questions

Do I need to update Chrome right away?

Yes, ideally today. Four Critical bugs mean it’s worth the thirty seconds, even though no attacks have been reported.

How do I know if I’m on Chrome 155?

Go to Settings, then About Chrome. The version number should start with 155.0.8059.

Is Chrome 155 safe to install?

Yes. It’s a normal stable release, and staying on an older version is the bigger risk.

Why hasn’t my Android phone got the update?

Google rolls Android updates out in stages, starting with a small share of users. It should reach you within days.

My advice: update now, restart, and make it a habit to relaunch Chrome at least once a week. With 247 fixes in one release, the browser is the app most worth keeping current. Don’t wait for headlines about active attacks.