Where does the bug appear (feature/product)?
Cursor IDE
Describe the Bug
During diagnostics from a network using Google DNS 8.8.8.8, if you ping agent.api5.cursor.sh, it resolves to
agent.api5.cursor.sh.cdn.cloudflare.net - 104.18.19.125
Directly accessing the link results in ERR_SSL_VERSION_OR_CIPHER_MISMATCH, and the IDE shows errors as in the screenshot. The likely cause is incorrectly configured SSL certificates: Fix VERSION_OR_CIPHER_MISMATCH · Cloudflare SSL/TLS docs
.
When using Quad9 DNS 149.112.112.112,
ping resolves to
agent.api5latency-useast.cursor.sh - 100.30.166.181
and there are no SSL issues; HTTP/2 works correctly. Therefore, the problem is related to Cloudflare settings.
There is also an issue in cursor-cli where some requests use an HTTP/2 approach, even though it is explicitly disabled in the settings, so it cannot be used reliably at this time.
My IP is from Ukraine, and DNS resolution may differ when queried from another region.
Steps to Reproduce
as described above
Screenshots / Screen Recordings
Operating System
Windows 10/11
MacOS
Linux
Current Cursor Version (Menu → About Cursor → Copy)
Version: 2.2.43 (system setup)
VSCode Version: 1.105.1
Commit: 32cfbe848b35d9eb320980195985450f244b3030
Date: 2025-12-19T06:06:44.644Z
Electron: 37.7.0
Chromium: 138.0.7204.251
Node.js: 22.20.0
V8: 13.8.258.32-electron.0
OS: Windows_NT x64 10.0.19045
Does this stop you from using Cursor
Yes - Cursor is unusable