---
id: CVE-2026-55883
title: 'Tilt: Cross-site WebSocket hijacking of the Tilt HUD stream'
summary: 'Tilt: Cross-site WebSocket hijacking of the Tilt HUD stream'
severity: high
cwe:
  - CWE-345
vendor: tilt-dev
product: github.com/tilt-dev/tilt
affected:
  - 'github.com/tilt-dev/tilt >= 0.24.0, <= 0.37.3'
patched:
  - github.com/tilt-dev/tilt 0.37.4
published: '2026-06-19'
updated: '2026-06-19'
source: GHSA
sourceUrl: 'https://github.com/advisories/GHSA-6m68-r693-78qx'
references:
  - url: 'https://github.com/tilt-dev/tilt/security/advisories/GHSA-6m68-r693-78qx'
  - url: 'https://github.com/tilt-dev/tilt/pull/6776'
  - url: 'https://github.com/tilt-dev/tilt/releases/tag/v0.37.4'
  - url: 'https://github.com/advisories/GHSA-6m68-r693-78qx'
tags:
  - ghsa
  - go
ingestedAt: '2026-06-22T15:59:08.205Z'
ecosystem: go
epss: 0.00262
epssPercentile: 0.18374
---

## Overview

## Summary
The Tilt HUD WebSocket (`/ws/view`) is gated by a CSRF token, but the token is served by an unauthenticated endpoint and the upgrader accepts any client that omits an `Origin` header. When the HUD is network-exposed, an attacker can open the HUD stream and read the developer's session state.

## Details
The upgrader accepts a connection when the `csrf` query parameter matches a process-wide token (`websocketCSRFToken`). That token is served as `text/plain` by an unauthenticated handler (`WebsocketToken`, mounted at `/api/websocket_token`), so any reachable caller can fetch it and connect to `/ws/view?csrf=<token>`. When the parameter does not match, the upgrader falls back to a same-origin check that returns true when the `Origin` header is absent, so a non-browser client that omits `Origin` is accepted anyway. The token has no per-session binding.

## Impact
An attacker who can reach the HUD listener can open the HUD WebSocket and receive the full view stream — session state, Tiltfile contents, resource statuses, and continued updates — defeating the intended anti-CSWSH protection.

### Conditions for exploitation
- Affected version in `>= 0.24.0, <= 0.37.3`.
- HUD bound to a non-loopback address (`tilt up --host 0.0.0.0`, or `TILT_HOST` set).
- Network reachability to the listener (default port `10350`).

### Not affected
- The default loopback-only bind is not reachable from the network.

## Workarounds
Use the default loopback bind (omit `--host`, unset `TILT_HOST`). No complete workaround short of upgrading for non-loopback deployments.

## Affected packages

- `github.com/tilt-dev/tilt >= 0.24.0, <= 0.37.3`

## Remediation

Upgrade to a patched release:

- `github.com/tilt-dev/tilt 0.37.4`