Origin Validation Error Affecting cline package, versions *
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-JS-CLINE-20158397
- published27 Sept 2026
- disclosed24 Sept 2026
- creditUnknown
Introduced: 24 Sep 2026
NewCVE-2026-59723 (opens in a new tab)How to fix?
A fix was pushed into the master branch but not yet published.
Overview
cline is an Autonomous coding agent CLI - capable of creating/editing files, running commands, using the browser, and more
Affected versions of this package are vulnerable to Origin Validation Error via missing WebSocket host and origin validation in the cline-hub dashboard server (apps/cline-hub/src/server.ts). An attacker on the same network can connect a malicious browser page to the dashboard WebSocket endpoint without presenting a valid origin or host header, because the server does not validate the Origin or Host of incoming WebSocket upgrade requests before the fix. This allows a cross-site WebSocket hijacking attack where a victim's browser, navigated to an attacker-controlled page, establishes a WebSocket connection to the local dashboard and relays commands, achieving full confidentiality, integrity, and availability impact over the desktop agent.
Note: This is only exploitable in the default configuration where roomSecret is undefined (no secret is set), which is the case when the server binds to the default local host 127.0.0.1.