Unable to verify first certificate

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

Using Cursor IDE, was working about an hour ago, now getting the following error:

Request ID: 2fe7969a-76ec-4023-a5d8-1cfaa5bedda5
[internal] unable to verify the first certificate
aae: [internal] unable to verify the first certificate
at Pnw (vscode-file://vscode-app…

Network diagnostic shows for SSL:
Result: Warning: Encrypted traffic is being intercepted by unrecognized certificate: C=US; O=PromptSecurity; CN=ca.prompt.security in 692ms

and for API/Ping/Chat/Agent:
[internal] unable to verify the first certificate

is this a setting on my end or something cursor server side?

Steps to Reproduce

Ask anything in agent mode

Operating System

Windows 10/11

Version Information

Version: 3.0.13 (user setup)
VSCode Version: 1.105.1
Commit: 48a15759f53cd5fc9b5c20936ad7d79847d914b0
Date: 2026-04-07T03:05:17.114Z
Layout: editor
Build Type: Stable
Release Track: Default
Electron: 39.8.1
Chromium: 142.0.7444.265
Node.js: 22.22.1
V8: 14.2.231.22-electron.0
OS: Windows_NT x64 10.0.22631

Does this stop you from using Cursor

Yes - Cursor is unusable

Hi there!

It appears that a third-party tool (Prompt Security) may be performing SSL inspection on your network! If Prompt Security was installed by your organization, we recommend reaching out to your IT administrators for configuration guidance, as we’re not familiar with this tool.

In the meantime, here are a few things you can try that are generally helpful when it comes to SSL inspection and Cursor:

  1. Obtain the Prompt Security root CA certificate from your IT team (.pem or .crt file), then either:

    • Install it in the Windows Trusted Root Certification Authorities store (Local Machine), or
    • Set a system environment variable: NODE_EXTRA_CA_CERTS=C:\path\to\prompt-security-ca.pem
  2. Enable system certificate settings by pressing Ctrl + Shift + P → “Open User Settings (UI)” → search for “Certificates” and enable the following for all profiles:

    • Http: System Certificates
    • Http > Experimental: System Certificates V2
  3. Disable HTTP/2 by navigating to Cursor Settings → Network (the same location where you ran the Network Diagnostic). This will fall back to HTTP/1.1, which tends to work better with inspection proxies.

Once you’ve completed any of these steps, please fully restart Cursor run the Network Diagnostic again!

I can also see that you’ve gotten in touch with [email protected] – for a complex issue like this with internal network considerations, highly recommend following up there if you hit a dead end.

turning on Experimental: System Certificates V2 worked, thanks so much!