CVE-2026-59723 Cline: Cross-Origin WebSocket Hijacking in Cline Hub Dashboard (`/browser` endpoint)
Attackers can hijack WebSocket connections to execute commands and modify settings if the local dashboard lacks a room secret.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-59723?
CVE-2026-59723 is a high-severity vulnerability in cline, published on 8 Jul 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
Cline is an autonomous coding agent as an SDK, IDE extension, or CLI assistant. Prior to 3.0.30, the Cline Hub dashboard server launched by the cline dashboard command accepts WebSocket connections on the /browser endpoint without validating the Origin header, and when ROOM_SECRET is unset for local 127.0.0.1 binds, isAuthorizedBrowserRequest() allows attacker-controlled websites to send desktopCommand frames that read workspace state, mutate MCP and provider settings, and trigger command execution when a provider or model is configured. This issue is fixed in version 3.0.30.
Weakness: CWE-346
Which versions are affected by CVE-2026-59723?
2 open source packages ship an affected version, including cline. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
cline npm | All versions | 3.0.30 |
cline npm | All versions | 3.0.30 |
Products include Cline Cline.
How do I fix CVE-2026-59723?
Upgrade cline to 3.0.30 or later.
Is CVE-2026-59723 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-59723 exists.
Other vulnerabilities in cline
Sources
Also known as GHSA-3cj3-hqcr-g934.