Google and Mozilla upgraded their Chrome and Firefox browsers this week, resolving a number of security issues. Please make sure your browser is up-to-date.

Some flaws allow remote code execution, or hacking, by malicious websites.

The best antivirus software for Windows and Mac will stop malware from being installed via your web browser, but you can never be too cautious.

The update to version 85.0.4183.121 of the desktop version of Chrome fixes 10 security flaws, five of which are classified as "high" in severity, according to Chrome's official blog.

According to the Common Vulnerabilities and Exposures Database, three of them allow remote hacking by specially designed malicious websites, and the other two make Chrome vulnerable to malicious browser extensions.

The Google Chrome browser on desktops is usually updated automatically on Windows, Mac, and Linux, as long as the browser is closed and restarted periodically. An update to version 85.0.4183.121 will be distributed to all users "in the coming weeks," the Chrome blog said.

To force an update to the Google Chrome browser, click on the three vertical dots in the upper right corner of the Chrome browser window, scroll down to Help, and select About Google Chrome from the menu that appears.

A new tab will open, check to see if you have the latest version, and if not, it will update. (Some Linux distributions push updates through the regular software update channel instead.)

Firefox 81.0, released yesterday (September 22), fixes six security flaws and applies to Android as well as the desktop OS. Three of them are described as "high" in potential impact, all of them related to memory corruption, one of the main reasons for vulnerabilities in all forms of software.

"With sufficient effort, we estimate that some of these could have been exploited to execute arbitrary code," Mozilla wrote in a security advisory.

Firefox81 also adds several new usability features, including the ability to pause and play audio and video from a keyboard or headphones, save and auto-fill credit card numbers, and fill out PDF forms. A pink and purple "Alpenglow" theme has also been added.

Like Chrome, Firefox updates automatically when the browser is launched.

To force a manual update, overlay the three lines in the upper right corner of the desktop browser window, scroll down and select "Help" at the bottom of the menu. select "About Firefox" and a pop-up window will appear, asking if your Firefox installation is up-to-date.

You can also download the full build of Firefox 81 for all supported desktop platforms from the Firefox FTP website.