[Mitigated] HTTP/2 Connection Failures with SSLV3_ALERT_HANDSHAKE_FAILURE, primary affecting users in Ukraine

Joop_B_Zoetemelk · January 25, 2026, 10:52am

Hey Colin, thanks for the fast follow up.

Please find below a screenshot of Cursor:

Vasyl_Hantsiuk · January 25, 2026, 7:16pm

How I fixed “Connection Error” / SSL Handshake Failure in Cursor

If you are seeing SSLV3_ALERT_HANDSHAKE_FAILURE (or SSL alert number 40) in your Cursor logs (Output → Cursor Tab), here is the most effective way to diagnose and fix it:

The VPN Test (Critical Diagnostic Step): Connecting to a VPN was the turning point for me. Once the VPN was active, Cursor reconnected instantly. This confirmed that the issue was not with the app or macOS itself, but with my ISP (Internet Service Provider) or Router.
The Root Cause: Some network equipment or ISP filters (DPI) fail to properly handle HTTP/2 multiplexed packets or TLS 1.3 handshakes. Because Cursor uses HTTP/2 for performance, certain project contexts or initialization requests can trigger a connection drop at the network level.
The Permanent Fix: You don’t need to keep the VPN on. The simplest fix is to switch Cursor to HTTP/1.1.
- Open Settings in Cursor.
- Navigate to Network → HTTP Compatibility Mode.
- Select HTTP/1.1.

After switching, the connection remains stable regardless of the project size, and there is no noticeable difference in AI response speed. If your connection is “flaky,” this is likely the culprit.

yadong_wang · January 26, 2026, 8:00am

I’ve found that when trying to make the large language model and API provided by the user compatible with our service, issues arise. For example, in a conversation with one round of agent dialogue, if I first use the large language model provided by the platform and then attempt to switch to my own configured large language model, it results in an error. However, if I use my own configured large language model from the very beginning of the conversation, no error occurs.

deniro · January 26, 2026, 4:41pm

Where does the bug appear (feature/product)?

Somewhere else…

Describe the Bug

“An unexpected error occurred on our servers. Please try again, or contact support if the issue persists.”

"Request ID: ec145e49-03d5-4a84-9dff-1a04ecc87933
[internal] 1288492106816:error:10000410:SSL routines:OPENSSL_internal:SSLV3_ALERT_HANDSHAKE_FAILURE:../../third_party/boringssl/src/ssl/tls_record.cc:486:SSL alert number 40

LTe: [internal] 1288492106816:error:10000410:SSL routines:OPENSSL_internal:SSLV3_ALERT_HANDSHAKE_FAILURE:../../third_party/boringssl/src/ssl/tls_record.cc:486:SSL alert number 40

at kmf (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:9095:38337)
at Cmf (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:9095:37240)
at $mf (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:9096:4395)
at ova.run (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:9096:8170)
at async qyt.runAgentLoop (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:34190:57047)
at async Wpc.streamFromAgentBackend (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:34239:7695)
at async Wpc.getAgentStreamResponse (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:34239:8436)
at async FTe.submitChatMaybeAbortCurrent (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:9170:14575)
at async Oi (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:32991:3808)"

Steps to Reproduce

reinstall didnt help
I dont use VPN
previous version (2.3) didnt help
cleaned cursor cash didnt help

Operating System

MacOS

Version Information

Version: 2.4.21 (Universal)
VSCode Version: 1.105.1
Commit: dc8361355d709f306d5159635a677a571b277bc0
Date: 2026-01-22T16:57:59.675Z
Build Type: Stable
Release Track: Default
Electron: 39.2.7
Chromium: 142.0.7444.235
Node.js: 22.21.1
V8: 14.2.231.21-electron.0
OS: Darwin arm64 24.4.0

Does this stop you from using Cursor

Yes - Cursor is unusable

Mr_Hornet · January 26, 2026, 8:18pm

Thank you for the update. I’ve tested version 2.4.21 and unfortunately, it is not functioning correctly. Specifically, it fails to work on HTTP/2, and performance is unacceptably slow when forced to use HTTP/1.1.

In contrast, the older version 2.2.44 works without any issues. I also attempted to resolve the problem by deleting all local data for the newer version, but this did not improve the situation.

As these critical issues prevent me from utilizing the latest features, I am left with no option but to consider canceling my subscription and moving to alternative services like Antigravity or Claude code, both of which I’ve found to work reliably.

A_Ku · January 27, 2026, 7:19am

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

after update, agent not working, connection error

Steps to Reproduce

ask agent anything

Expected Behavior

should work without errors

Operating System

MacOS

Version Information

Version: 2.4.21
VSCode Version: 1.105.1
Commit: dc8361355d709f306d5159635a677a571b277bc0
Date: 2026-01-22T16:57:59.675Z
Build Type: Stable
Release Track: Default
Electron: 39.2.7
Chromium: 142.0.7444.235
Node.js: 22.21.1
V8: 14.2.231.21-electron.0
OS: Darwin arm64 24.5.0

For AI issues: which model did you use?

auto

Additional Information

Request ID: 12719631-2a81-4d1e-8ad6-fd81266256ac
[internal] 1322851578560:error:10000410:SSL routines:OPENSSL_internal:SSLV3_ALERT_HANDSHAKE_FAILURE:../../third_party/boringssl/src/ssl/tls_record.cc:486:SSL alert number 40

LTe: [internal] 1322851578560:error:10000410:SSL routines:OPENSSL_internal:SSLV3_ALERT_HANDSHAKE_FAILURE:../../third_party/boringssl/src/ssl/tls_record.cc:486:SSL alert number 40

at kmf (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:9095:38337)
at Cmf (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:9095:37240)
at $mf (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:9096:4395)
at ova.run (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:9096:8170)
at async qyt.runAgentLoop (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:34190:57047)
at async Wpc.streamFromAgentBackend (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:34239:7695)
at async Wpc.getAgentStreamResponse (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:34239:8436)
at async FTe.submitChatMaybeAbortCurrent (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:9170:14575)
at async Oi (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:32991:3808)

Does this stop you from using Cursor

Yes - Cursor is unusable

SRV · January 27, 2026, 9:29am

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

Any attempt to use the chat results in a persistent system error message. (on screenshot)

Steps to Reproduce

just write something to agent chat

Screenshots / Screen Recordings

Operating System

MacOS

Version Information

Version: 2.4.21
VSCode Version: 1.105.1
Commit: dc8361355d709f306d5159635a677a571b277bc0
Date: 2026-01-22T16:57:59.675Z (4 days ago)
Build Type: Stable
Release Track: Default
Electron: 39.2.7
Chromium: 142.0.7444.235
Node.js: 22.21.1
V8: 14.2.231.21-electron.0
OS: Darwin arm64 24.4.0

Additional Information

Request ID: 567b796b-fc94-47c2-ba82-ebcfc134d47f
[internal] 1185412694656:error:10000410:SSL routines:OPENSSL_internal:SSLV3_ALERT_HANDSHAKE_FAILURE:../../third_party/boringssl/src/ssl/tls_record.cc:486:SSL alert number 40

LTe: [internal] 1185412694656:error:10000410:SSL routines:OPENSSL_internal:SSLV3_ALERT_HANDSHAKE_FAILURE:../../third_party/boringssl/src/ssl/tls_record.cc:486:SSL alert number 40

at kmf (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:9095:38337)
at Cmf (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:9095:37240)
at $mf (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:9096:4395)
at ova.run (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:9096:8170)
at async qyt.runAgentLoop (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:34190:57047)
at async Wpc.streamFromAgentBackend (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:34239:7695)
at async Wpc.getAgentStreamResponse (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:34239:8436)
at async FTe.submitChatMaybeAbortCurrent (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:9170:14575)
at async Oi (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:32991:3808)

Does this stop you from using Cursor

Yes - Cursor is unusable

AndriiV · January 27, 2026, 10:39am

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

OS: Ubuntu 22
After installing the last update(cursor_2.4.21_amd64.deb) - cursor does not work

An unexpected error occurred on our servers. Please try again, or contact support if the issue persists.
Request ID: 5cec4ff0-63b5-4430-bcfc-afa47b3c0aac
[internal] 23965918365888:error:10000410:SSL routines:OPENSSL_internal:SSLV3_ALERT_HANDSHAKE_FAILURE:../../third_party/boringssl/src/ssl/tls_record.cc:486:SSL alert number 40

LTe: [internal] 23965918365888:error:10000410:SSL routines:OPENSSL_internal:SSLV3_ALERT_HANDSHAKE_FAILURE:../../third_party/boringssl/src/ssl/tls_record.cc:486:SSL alert number 40

at kmf (vscode-file://vscode-app/tmp/.mount_CursorWnfdwm/usr/share/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:9095:38337)
at Cmf (vscode-file://vscode-app/tmp/.mount_CursorWnfdwm/usr/share/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:9095:37240)
at $mf (vscode-file://vscode-app/tmp/.mount_CursorWnfdwm/usr/share/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:9096:4395)
at ova.run (vscode-file://vscode-app/tmp/.mount_CursorWnfdwm/usr/share/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:9096:8170)
at async qyt.runAgentLoop (vscode-file://vscode-app/tmp/.mount_CursorWnfdwm/usr/share/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:34190:57047)
at async Wpc.streamFromAgentBackend (vscode-file://vscode-app/tmp/.mount_CursorWnfdwm/usr/share/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:34239:7695)
at async Wpc.getAgentStreamResponse (vscode-file://vscode-app/tmp/.mount_CursorWnfdwm/usr/share/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:34239:8436)
at async FTe.submitChatMaybeAbortCurrent (vscode-file://vscode-app/tmp/.mount_CursorWnfdwm/usr/share/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:9170:14575)
at async Object.Oi [as onSubmit] (vscode-file://vscode-app/tmp/.mount_CursorWnfdwm/usr/share/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:32991:3808)
at async vscode-file://vscode-app/tmp/.mount_CursorWnfdwm/usr/share/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:32965:59943

Steps to Reproduce

install the latest version on Ubuntu.
Try to use agent - see the error

Expected Behavior

working agent

Operating System

Linux

Version Information

Version: 2.4.21
VSCode Version: 1.105.1
Commit: dc8361355d709f306d5159635a677a571b277bc0
Date: 2026-01-22T16:57:59.675Z
Build Type: Stable
Release Track: Default
Electron: 39.2.7
Chromium: 142.0.7444.235
Node.js: 22.21.1
V8: 14.2.231.21-electron.0
OS: Linux x64 6.8.0-90-generic

Does this stop you from using Cursor

Yes - Cursor is unusable

Amir_Asaadi · January 27, 2026, 12:55pm

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

Today I am unable to connect to agents and network diagnostic show the following error:
[2026-01-27T12:41:12.895Z] Start
[2026-01-27T12:41:14.160Z] Error: ConnectError: [internal] 275200:error:10000410:SSL routines:OPENSSL_internal:SSLV3_ALERT_HANDSHAKE_FAILURE:…\third_party\boringssl\src\ssl\tls_record.cc:486:SSL alert number 40

if I change protocol to http/1.1 the error changes to :
[2026-01-27T12:51:21.502Z] Start
[2026-01-27T12:51:22.107Z] Error: ConnectError: [permission_denied] HTTP 403

I’ve updated the IDE today to version 2.4.1 and above the top issue a new issue apeared:
IDE constantly says: “Chat failed to fully load. Please reload the window to try again”!

Steps to Reproduce

try to run any agent

Operating System

Windows 10/11

Version Information

Version: 2.4.21 (user setup)
VSCode Version: 1.105.1
Commit: dc8361355d709f306d5159635a677a571b277bc0
Date: 2026-01-22T16:57:59.675Z
Build Type: Stable
Release Track: Default
Electron: 39.2.7
Chromium: 142.0.7444.235
Node.js: 22.21.1
V8: 14.2.231.21-electron.0
OS: Windows_NT x64 10.0.20348

For AI issues: which model did you use?

all

Does this stop you from using Cursor

Yes - Cursor is unusable

Marko_Tyshchenk · January 27, 2026, 4:28pm

Same issue here. Here generated summaty/ Guys please fix, or help how to fix it. Working using http/1 is too slow((

Bug Report: HTTP/2 SSL Handshake Failure in Cursor IDE

## Summary

Cursor IDE fails to establish HTTP/2 connections for API, Chat, Agent, and Ping services with SSL handshake errors, even though HTTP/2 connectivity tests pass. The issue affects all streaming/bidirectional connections while simple HTTP/2 requests work correctly.

## Environment

- **Cursor Version:** v22.21.1

- **OS:** Ubuntu 24.04.3 LTS (Linux 6.8.0-45-generic)

- **OpenSSL Version:** 3.0.13 30 Jan 2024

- **Architecture:** x86_64

## Issue Description

When HTTP/2 is enabled (default), Cursor fails to establish connections to its backend services (API, Chat, Agent, Ping) with SSL handshake failures. The error occurs specifically with gRPC/streaming connections over HTTP/2, while basic HTTP/2 connectivity tests succeed.

## Error Messages

```

Error: ConnectError: [internal] 69045895055552:error:10000410:SSL routines:OPENSSL_internal:SSLV3_ALERT_HANDSHAKE_FAILURE:../../third_party/boringssl/src/ssl/tls_record.cc:486:SSL alert number 40

```

This error appears for:

- API connections

- Ping operations

- Chat streaming connections

- Agent streaming connections

## Steps to Reproduce

1. Launch Cursor IDE v22.21.1

2. Ensure HTTP/2 is enabled (default, or set `cursor.general.disableHttp2: false`)

3. Attempt to use any feature requiring backend connectivity:

- Open Chat (Cmd/Ctrl+L)

- Use Agent features

- Any API-dependent functionality

4. Observe SSL handshake failure errors in the console/network diagnostic

## Expected Behavior

Cursor should successfully establish HTTP/2 connections to backend services, including gRPC streaming connections for Chat, Agent, and Ping services.

## Actual Behavior

- **HTTP/2 Diagnostic Test:** Passes (connects to `api2.cursor.sh` successfully)

- **SSL/TLS Test:** Passes (certificate validation successful)

- **API Connections:** Fails with SSL handshake error

- **Chat/Agent/Ping:** Fails with SSL handshake error

## Network Diagnostic Results

```

HTTP/2:

[2026-01-27T16:00:25.870Z] Start

[2026-01-27T16:00:25.991Z] Host: api2.cursor.sh

[2026-01-27T16:00:25.992Z] Protocol: h2

[2026-01-27T16:00:25.992Z] Result: true in 122ms

SSL:

[2026-01-27T16:00:26.097Z] URL: https://api2.cursor.sh/

[2026-01-27T16:00:26.097Z] Status: 200

[2026-01-27T16:00:26.097Z] IP: 104.18.18.125

[2026-01-27T16:00:26.097Z] Result: true in 227ms

API:

[2026-01-27T16:00:26.101Z] Error: ConnectError: [internal] 69045895055552:error:10000410:SSL routines:OPENSSL_internal:SSLV3_ALERT_HANDSHAKE_FAILURE:../../third_party/boringssl/src/ssl/tls_record.cc:486:SSL alert number 40

```

## Workaround

Setting `cursor.general.disableHttp2: true` in settings.json allows connections to work, but forces HTTP/1.1, which degrades performance and may not be a long-term solution.

## Technical Analysis

1. **Server-side HTTP/2 support is confirmed:**

- `openssl s_client` successfully negotiates HTTP/2 via ALPN

- Server supports TLS 1.3 with modern cipher suites

- ALPN protocol negotiation works correctly

2. **The issue appears to be client-side:**

- Cursor uses BoringSSL for SSL/TLS operations

- The failure occurs specifically with bidirectional/streaming connections (gRPC over HTTP/2)

- Simple HTTP/2 requests work, suggesting the issue is with how Cursor’s BoringSSL handles HTTP/2 streams

3. **Possible root causes:**

- BoringSSL client implementation issue with HTTP/2 bidirectional streams

- ALPN negotiation failure for gRPC/streaming connections

- Incompatibility between system OpenSSL 3.0.13 and Cursor’s BoringSSL for HTTP/2 stream handling

- Certificate validation or cipher suite negotiation issue specific to streaming connections

## Additional Information

- No proxy configuration detected

- No firewall rules blocking connections

- System SSL/TLS configuration appears standard

- Issue persists across application restarts

- The `http.systemCertificates` setting has no effect on the issue

## Related Issues

Based on community forum discussions, this appears to be a known issue affecting users in certain environments, particularly:

- Users behind corporate proxies (though not applicable in this case)

- Users with specific SSL/TLS configurations

- Recent Cursor versions (0.46+) where `disableHttp2` setting may not fully prevent HTTP/2 usage

## Request

Please investigate:

1. Why BoringSSL in Cursor fails to establish HTTP/2 connections for gRPC/streaming services

2. Whether there’s a compatibility issue with OpenSSL 3.0.13

3. If there’s a configuration option or fix to properly support HTTP/2 streaming connections

4. Consider providing better error messages or fallback mechanisms

## Impact

**Severity:** High - Core functionality (Chat, Agent) is unusable without workaround

**Frequency:** 100% - Occurs on every connection attempt when HTTP/2 is enabled

**Workaround Available:** Yes (disable HTTP/2, but with performance penalty)

-–

**Reported by:** User experiencing the issue

**Date:** 2026-01-27

**Priority:** High - Blocks core features

xpp4ik · January 27, 2026, 2:47pm

Request ID: f8f63d5c-ded6-4d9c-9f37-11341626cb48
[internal] 277120:error:10000410:SSL routines:OPENSSL_internal:SSLV3_ALERT_HANDSHAKE_FAILURE:…\third_party\boringssl\src\ssl\tls_record.cc:486:SSL alert number 40

LTe: [internal] 277120:error:10000410:SSL routines:OPENSSL_internal:SSLV3_ALERT_HANDSHAKE_FAILURE:…\third_party\boringssl\src\ssl\tls_record.cc:486:SSL alert number 40

at kmf (vscode-file://vscode-app/e:/programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:9095:38337)
at Cmf (vscode-file://vscode-app/e:/programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:9095:37240)
at $mf (vscode-file://vscode-app/e:/programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:9096:4395)
at ova.run (vscode-file://vscode-app/e:/programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:9096:8170)
at async qyt.runAgentLoop (vscode-file://vscode-app/e:/programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:34190:57047)
at async Wpc.streamFromAgentBackend (vscode-file://vscode-app/e:/programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:34239:7695)
at async Wpc.getAgentStreamResponse (vscode-file://vscode-app/e:/programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:34239:8436)
at async FTe.submitChatMaybeAbortCurrent (vscode-file://vscode-app/e:/programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:9170:14575)
at async Object.Oi [as onSubmit] (vscode-file://vscode-app/e:/programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:32991:3808)
at async vscode-file://vscode-app/e:/programs/cursor/resources/app/out/vs/workbench/workbench.desktop.main.js:32965:59943

system · January 27, 2026, 2:47pm

Hi there!

We detected that this may be a bug report, so we’ve moved your post to the Bug Reports category.

To help us investigate and fix this faster, could you edit your original post to include the details from the template below?

Bug Report Template - Click to expand

Where does the bug appear (feature/product)?

Cursor IDE
Cursor CLI
Background Agent (GitHub, Slack, Web, Linear)
BugBot
Somewhere else…

Describe the Bug
A clear and concise description of what the bug is.

Steps to Reproduce
How can you reproduce this bug? We have a much better chance at fixing issues if we can reproduce them!

…
…
…

Expected Behavior
What is meant to happen here that isn’t working correctly?

Screenshots / Screen Recordings
If applicable, attach images or videos (.jpg, .png, .gif, .mp4, .mov)

Operating System

Windows 10/11
MacOS
Linux

Version Information

For Cursor IDE: Menu → About Cursor → Copy
For Cursor CLI: Run agent about in your terminal

IDE:
Version: 2.xx.x
VSCode Version: 1.105.1
Commit: ......

CLI:
CLI Version 2026.01.17-d239e66

For AI issues: which model did you use?
Model name (e.g., Sonnet 4, Tab…)

For AI issues: add Request ID with privacy disabled
Request ID: f9a7046a-279b-47e5-ab48-6e8dc12daba1
For Background Agent issues, also post the ID: bc-…

Additional Information
Add any other context about the problem here.

Does this stop you from using Cursor?

Yes - Cursor is unusable
Sometimes - I can sometimes use Cursor
No - Cursor works, but with this issue

The more details you provide, the easier it is for us to reproduce and fix the issue. Thanks!

Serhii_Boiko · January 28, 2026, 7:57am

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

Request ID: d5f0a0c7-38d4-4f2d-8b7d-3fa66352b3ad
[internal] 1185412691520:error:10000410:SSL routines:OPENSSL_internal:SSLV3_ALERT_HANDSHAKE_FAILURE:../../third_party/boringssl/src/ssl/tls_record.cc:486:SSL alert number 40

LTe: [internal] 1185412691520:error:10000410:SSL routines:OPENSSL_internal:SSLV3_ALERT_HANDSHAKE_FAILURE:../../third_party/boringssl/src/ssl/tls_record.cc:486:SSL alert number 40

at kmf (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:9095:38337)
at Cmf (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:9095:37240)
at $mf (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:9096:4395)
at ova.run (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:9096:8170)
at async qyt.runAgentLoop (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:34190:57047)
at async Wpc.streamFromAgentBackend (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:34239:7695)
at async Wpc.getAgentStreamResponse (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:34239:8436)
at async FTe.submitChatMaybeAbortCurrent (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:9170:14575)

Steps to Reproduce

just ask agent or ask mode, then error

Screenshots / Screen Recordings

Operating System

MacOS

Version Information

Version: 2.4.21
VSCode Version: 1.105.1
Commit: dc8361355d709f306d5159635a677a571b277bc0
Date: 2026-01-22T16:57:59.675Z
Build Type: Stable
Release Track: Default
Electron: 39.2.7
Chromium: 142.0.7444.235
Node.js: 22.21.1
V8: 14.2.231.21-electron.0
OS: Darwin arm64 24.6.0

Does this stop you from using Cursor

Yes - Cursor is unusable

Activator · January 28, 2026, 1:14pm

Когда выйдет фикс Cursor для HTTP/2 ???

Eugene_K · January 28, 2026, 2:22pm

This issue has been open for ~4 months with no permanent fix, no clear RCA, and no visible progress.

We have repeatedly demonstrated that clearing Cursor’s internal state immediately resolves the problem. This makes the failure mode both reproducible and diagnosable. At this point, the lack of root cause identification is not a complexity issue - it is a prioritization issue.

We are not able to rely on a tool where critical functionality degrades over time due to state corruption and the only workaround is manual state resets.

Because of this, we are planning to stop using Cursor and do not intend to renew the subscription.

If there is an actual root-cause analysis, fix timeline, or engineering owner for this issue, now would be the time to share it. Otherwise, from our side this is considered unresolved and blocking.

lnoks · January 28, 2026, 12:24pm

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

Internal Error
An unexpected error occurred on our servers. Please try again, or contact support if the issue persists

Request ID: d309e90d-66e4-48ed-89b3-64bd793a6d6d
[internal] 1254132363968:error:10000410:SSL routines:OPENSSL_internal:SSLV3_ALERT_HANDSHAKE_FAILURE:../../third_party/boringssl/src/ssl/tls_record.cc:486:SSL alert number 40

LTe: [internal] 1254132363968:error:10000410:SSL routines:OPENSSL_internal:SSLV3_ALERT_HANDSHAKE_FAILURE:../../third_party/boringssl/src/ssl/tls_record.cc:486:SSL alert number 40

at Gmf (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:9095:38348)
at Hmf (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:9095:37251)
at rpf (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:9096:4395)
at fva.run (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:9096:8170)
at async Hyt.runAgentLoop (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:34196:57047)
at async Zpc.streamFromAgentBackend (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:34245:7695)
at async Zpc.getAgentStreamResponse (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:34245:8436)
at async FTe.submitChatMaybeAbortCurrent (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:9170:14575)
at async Object.Ei [as onSubmit] (vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:32994:3808)
at async vscode-file://vscode-app/Applications/Cursor.app/Contents/Resources/app/out/vs/workbench/workbench.desktop.main.js:32968:59730

Steps to Reproduce

Send any prompt with any model in chat UI

Operating System

MacOS

Version Information

Version: 2.4.22
VSCode Version: 1.105.1
Commit: 618c607a249dd7fd2ffc662c6531143833bebd40
Date: 2026-01-26T22:51:47.692Z
Build Type: Stable
Release Track: Default
Electron: 39.2.7
Chromium: 142.0.7444.235
Node.js: 22.21.1
V8: 14.2.231.21-electron.0
OS: Darwin arm64 24.6.0

For AI issues: which model did you use?

Opus 4.5, Sonnet 4.5, Composer 1, Auto mode

For AI issues: add Request ID with privacy disabled

Request ID: d309e90d-66e4-48ed-89b3-64bd793a6d6d

Does this stop you from using Cursor

Yes - Cursor is unusable

Vadim_Ignatiev · January 28, 2026, 5:17pm

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

Hi everyone,

I’m running into a persistent issue with Cursor that started immediately after a recent update, and I’ve been unable to resolve it despite extensive troubleshooting.

Problem description
Cursor fails to connect due to an SSL/TLS handshake error. Most AI-related features don’t work (chat, agent, API checks), and network diagnostics consistently report an SSL handshake failure.

Typical error looks like:

SSLV3_ALERT_HANDSHAKE_FAILURE (alert number 40)

What I’ve already tried:

Fully updated Windows

Disabled antivirus and Windows Firewall

Ran Cursor as administrator

Logged out and logged back in

Reinstalled Cursor (latest version)

Installed a newer Cursor update when it became available (still broken)

Tried switching AI models (same result)

Created and tested under a separate Windows user account → same issue

The problem persists across restarts and clean installs

Important detail:
The issue started right after a Cursor update. Cursor was working normally before that.

Also worth noting:

The problem reproduces on multiple Windows user accounts

Reinstalling Cursor did not help

This strongly suggests it’s not related to local user settings or corrupted app data

At this point I’m out of ideas on the client side.
Has anyone else encountered a similar SSL/TLS handshake issue with Cursor recently?
Is this a known problem, or is there any workaround I might be missing?

Any insight from Cursor devs or other users would be greatly appreciated, as this is currently blocking my work.

Thanks!

Steps to Reproduce

Steps to reproduce

Install Cursor (latest stable version) on Windows.

Launch Cursor and log in to an account.

Open any project (or even without a project).

Try to use any AI feature, for example:

Open the Chat / Agent panel

Send any message (e.g. “Hello”)

Cursor immediately fails with a server/network error.

Go to Cursor Settings → Network.

Click “Run Diagnostics” / “Check Network Connections”.

Diagnostics report SSL/TLS errors (SSL handshake failure) for multiple services (API, Chat, Agent, Ping).

Result:
AI features do not work. Network diagnostics consistently show SSL handshake errors.

Expected Behavior

Cursor successfully connects to backend services and AI features work normally.

Screenshots / Screen Recordings

Operating System

Windows 10/11

Version Information

Version: 2.4.22 (user setup)
VSCode Version: 1.105.1
Commit: 618c607a249dd7fd2ffc662c6531143833bebd40
Date: 2026-01-26T22:51:47.692Z
Build Type: Stable
Release Track: Default
Electron: 39.2.7
Chromium: 142.0.7444.235
Node.js: 22.21.1
V8: 14.2.231.21-electron.0
OS: Windows_NT x64 10.0.26100

For AI issues: which model did you use?

Auto

Does this stop you from using Cursor

Yes - Cursor is unusable

tmm1 · January 28, 2026, 7:23pm

Is there anyone actively hitting this issue and available to do a screenshare for debugging? Send me a DM

tmm1 · January 28, 2026, 8:22pm

We have been able to reproduce this issue using an Ukranian VPN and are investigation. There should be a mitigation in place now while we update with a long term fix.

lp1641 · January 29, 2026, 10:09am

I’m from Ukraine as well.
Yesterday the network test was failing but I’ve checked just now, and it started working.

Whatever you did I wish you keep it.)

Version: 2.4.22 (user setup)
VSCode Version: 1.105.1
Commit: 618c607a249dd7fd2ffc662c6531143833bebd40
Date: 2026-01-26T22:51:47.692Z
Build Type: Stable
Release Track: Default
Electron: 39.2.7
Chromium: 142.0.7444.235
Node.js: 22.21.1
V8: 14.2.231.21-electron.0
OS: Windows_NT x64 10.0.26200

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[Mitigated] HTTP/2 Connection Failures with SSLV3_ALERT_HANDSHAKE_FAILURE, primary affecting users in Ukraine

How I fixed “Connection Error” / SSL Handshake Failure in Cursor

Where does the bug appear (feature/product)?

Describe the Bug

Steps to Reproduce

Operating System

Version Information

Does this stop you from using Cursor

Where does the bug appear (feature/product)?

Describe the Bug

Steps to Reproduce

Expected Behavior

Operating System

Version Information

For AI issues: which model did you use?

Additional Information

Does this stop you from using Cursor

Where does the bug appear (feature/product)?

Describe the Bug

Steps to Reproduce

Screenshots / Screen Recordings

Operating System

Version Information

Additional Information

Does this stop you from using Cursor

Where does the bug appear (feature/product)?

Describe the Bug

Steps to Reproduce

Expected Behavior

Operating System

Version Information

Does this stop you from using Cursor

Where does the bug appear (feature/product)?

Describe the Bug

Steps to Reproduce

Operating System

Version Information

For AI issues: which model did you use?

Does this stop you from using Cursor

Bug Report: HTTP/2 SSL Handshake Failure in Cursor IDE

Where does the bug appear (feature/product)?

Describe the Bug

Steps to Reproduce

Screenshots / Screen Recordings

Operating System

Version Information

Does this stop you from using Cursor

Where does the bug appear (feature/product)?

Describe the Bug

Steps to Reproduce

Operating System

Version Information

For AI issues: which model did you use?

For AI issues: add Request ID with privacy disabled

Does this stop you from using Cursor

Where does the bug appear (feature/product)?

Describe the Bug

Steps to Reproduce

Expected Behavior

Screenshots / Screen Recordings

Operating System

Version Information

For AI issues: which model did you use?

Does this stop you from using Cursor

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