MacOS 26 (Tahoe) lag due to electron bug

Support Bug Reports
1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

Latest Cursor is using Electron version 34.5.8. There was a bug fixed in electron that affects MacOS 26 (Tahoe) and Cursor needs to update the electron version in order to get this fix.

The specific Electron versions that contain the fix for the issue are v39.0.0-alpha.7, v38.2.0, v37.6.0 and v36.9.2.

Steps to Reproduce

Just use the app on Macos 26

Operating System

MacOS

Current Cursor Version (Menu → About Cursor → Copy)

Version: 1.7.39
VSCode Version: 1.99.3
Commit: a9c77ceae65b77ff772d6adfe05f24d8ebcb2790
Date: 2025-10-08T00:33:20.352Z
Electron: 34.5.8
Chromium: 132.0.6834.210
Node.js: 20.19.1
V8: 13.2.152.41-electron.0
OS: Darwin arm64 25.0.0

Does this stop you from using Cursor

No - Cursor works, but with this issue

1 Like
2

The current workaround for this is running “launchctl setenv CHROME_HEADLESS” in the terminal

Hopefully cursor fixes this bug soon

3

Hey, thanks for the report. We’ll investigate this.

1 Like
5

fix: MacOS 26 Tahoe - stop overriding private cornerMask API to fix WindowServer GPU load by avarayr · Pull Request #48376 · electron/electron · GitHub this is the related issue

2 Likes
6

Any update on this?

1 Like
7

I find it wild that Cursor is one of the last companies to address this bug. Even Salesforce owned companies like Slack have already managed to fix it.

8

We have already removed the shadow in September which fixed this performance issue of Electron on MacOS 26.0 and were one of the first companies to do so…

Are you still having that issue and how are you affected?

9

I tried to using this script(detect-electron-apps-using-cornermask.sh) to check, seems cursor is not fixed.

10

Ok, Dean already sent the issue to the team, though I do not notice any lag on MacOS due to fix already applied on our side.

Note that the script only checks for specific markers and not if a fix was applied.

12

please pass this to engineering

Shadows in cursor are only disabled if parseFloat(os.release()) === 25

image
image728×224 13 KB

Many of us are running MacOS 25.1 beta (in hopes that one of these betas would fix the electron bug)
The bug exists in 25.0.0, 25.0.1, and 25.1.* betas

The code needs to be modified to disable the shadows

image
image940×256 20.2 KB

3 Likes
13

P.S. I’m the author of the Shamelectron website, and i’d be happy to give cursor a “Fixed” status after you guys correct the version check.

3 Likes
14

@condor Any update on this issue?

1 Like
15

good news everyone, Cursor Nightly (1.9.0-pre.1.patch.0 and up) contain a hotfix that fixes this issue without disabling shadows.

Cursor Nightly is now marked as fixed on shamelectron.

As of now the fix is gated to 26.0.0 and 26.0.1 , those on 26.1 beta will receive this fix possibly tomorrow

16

Honestly its embarrassing how long this is taking. 26.1 beta still has the same issue and is the only app on my mac that has not been updated!

2 Likes
17

This topic was automatically closed 22 days after the last reply. New replies are no longer allowed.

18

Hey everyone, we’ve updated the version to 37.7.0.