Edge 155.0.4283.45 security update: install and verify on your PC

If Microsoft Edge is the browser you actually use on a home Windows or Mac computer, check the version today. On October 8, 2026, Microsoft shipped Stable 155.0.4283.45. The Edge security release notes say that build incorporates the latest security updates from the Chromium project. The same day’s Stable channel notes list it as the main Stable release for Edge 155.

You do not need a CVE scavenger hunt. You need that build running, then a clean relaunch.

This is separate from the earlier Edge 154.0.4258.62 security update we covered for October 5/6. That was still on the 154 train. 155.0.4283.45 is a new major Stable line. Updating Chrome does not update Edge. Updating Edge does not update Chrome.

What Microsoft shipped on October 8

From Microsoft’s security notes for October 08, 2026:

• Stable Microsoft Edge 155.0.4283.45 incorporates the latest Chromium security updates
• Details point at Microsoft’s Security Update Guide

The Stable channel page marks Version 155.0.4283.45 (October 8, 2026) as the main Stable release for Edge 155. Extended Stable also moved that day to 152.0.4191.122. Most home users are on normal Stable, not Extended Stable. If you never changed channels, you want the 155.0.4283.45 line.

Edge 155 also carries web-platform changes described in Microsoft’s Edge 155 platform release notes (dated for the October 8, 2026 release). Those notes are useful if you care about developer features. They are not a substitute for being on the security build. For a home user, the job is still: install, relaunch, verify.

Stable notes for 155 also mention rollout work around the web platform unload event default (moving toward not firing unload handlers unless a site opts in). That is background for sites and extensions. It is not a reason to skip the security update.

Why 154.x is not enough anymore

If edge://version still shows 154.0.4258.62 or any other 154.0.4258.x build, you are on last week’s major train. Edge 155 is the new Stable line. The October 5 Edge 154 security package mattered. This package is a separate jump.

Same habit every time:

1. Update
2. Fully quit and relaunch
3. Prove it with edge://version

Downloaded is not running. The version page is the receipt.

How to update and verify on a home PC or Mac

1. Open Microsoft Edge on the computer you browse with.
2. Check for updates:
   • Windows / Linux: Menu (three dots) → Help and feedback → About Microsoft Edge.
   • Mac: Edge menu → About Microsoft Edge.
3. Stay on that page until the download finishes and Edge offers a restart, or until it already shows 155.0.4283.45 (or a newer 155.0.4283.x if Microsoft ships one after this article).
4. Restart when prompted. Do not click Later and leave old windows open for hours.
5. If the version still looks old, fully quit Edge (every window). On Windows, confirm no leftover msedge.exe helpers in Task Manager. On Mac, use Edge → Quit Microsoft Edge. Open Edge again.
6. Type edge://version in the address bar. You want 155.0.4283.45 or newer on the same 155 train.
7. Repeat on other machines you use, including a laptop that sleeps with Edge still open and any shared family PC.

If About Edge says an update is coming but does not offer 155 yet, give Stable a day, then check again. Microsoft stages these.

Android and iOS Edge, separately

Desktop Edge updates do not patch the phone apps. Edge on Android and iOS updates through Google Play or the App Store on their own schedules. Check the store listing on your phone if that is how you browse, and open the app once after it updates so the new build actually launches.

Do this / don’t do that

Do

• Force About Microsoft Edge, relaunch, and confirm edge://version shows 155.0.4283.45 or newer.
• Update Chrome, Firefox, Safari, and Brave on their own pages if you use them. Edge is only one browser.
• Fully quit leftover Edge processes after an update prompt.
• Treat a new major Stable security build as “install today,” not “install when I remember on Sunday.”

Don’t

• Do not stop at 154.0.4258.62 because you already “did the Edge 154 update.”
• Do not assume a Windows Update reboot alone refreshed Edge if edge://version is still old.
• Do not invent exploit details for Chromium bugs that Microsoft has not listed on the Edge security page yet.
• Do not download random “Edge offline installer” packs from third-party sites. Use Edge’s own About page or Microsoft’s download links.

Bottom line

Microsoft’s October 8, 2026 Stable update ships Edge 155.0.4283.45 with Chromium security ingest (security release notes, Stable channel notes, platform notes for 155). This is beyond the earlier 154.0.4258.62 package. On your own computer: open About Microsoft Edge, install, fully quit and relaunch, confirm edge://version. That is the whole job.

Image: Microsoft Edge security marketing art (microsoft.com/edge).