Is CVE-2026-59723 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-59723 being exploited in the wild.

How severe is CVE-2026-59723?

High severity, with a CVSS score of 8.8, published 8 July 2026.

Which products and versions are affected?

Cline Hub < 3.0.30; cline (npm) SEMVER:introduced=0,fixed=3.0.30.

Is there a fix for CVE-2026-59723?

Yes. cline (npm): upgrade to 3.0.30 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-59723 attacked?

It is attacked from the adjacent network, in a web application.

Am I affected by CVE-2026-59723?

Check whether you run Cline Hub or cline (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-59723: Cline Hub dashboard Cross-Site WebSocket Hijacking

Q: Which products and versions are affected?

Cline Hub < 3.0.30; cline (npm) SEMVER:introduced=0,fixed=3.0.30.

Q: Is there a fix for CVE-2026-59723?

Yes. cline (npm): upgrade to 3.0.30 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-59723 attacked?

It is attacked from the adjacent network, in a web application.

Q: Am I affected by CVE-2026-59723?

Check whether you run Cline Hub or cline (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-59723 · Severity: high · CVSS 8.8 · Published 2026-07-08

Cline Hub is a local dashboard for the Cline AI code assistant that developers launch on their machine. The dashboard's WebSocket endpoint fails to validate the origin of incoming connections, allowing any website visited by the developer to inject malicious MCP (Model Context Protocol) servers with arbitrary shell commands. Since dashboard sessions auto-approve all tool use by default, this leads to command execution under the developer's account when the injected server is activated.

Technologies: cline (npm). Vendors: Cline, npm.

Quick answers

Is CVE-2026-59723 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-59723 being exploited in the wild.
How severe is CVE-2026-59723?: High severity, with a CVSS score of 8.8, published 8 July 2026.
Which products and versions are affected?: Cline Hub < 3.0.30; cline (npm) SEMVER:introduced=0,fixed=3.0.30.
Is there a fix for CVE-2026-59723?: Yes. cline (npm): upgrade to 3.0.30 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-59723 attacked?: It is attacked from the adjacent network, in a web application.
Am I affected by CVE-2026-59723?: Check whether you run Cline Hub or cline (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

cline (npm): upgrade to 3.0.30 or later
```
npm install cline@3.0.30
```

Technical details

The vulnerability is a cross-origin WebSocket hijacking (CSWSH) in the Cline Hub dashboard's `/browser` endpoint. Root cause: (1) when ROOM_SECRET environment variable is unset (the default for localhost binds), the isAuthorizedBrowserRequest() function returns true unconditionally, bypassing all authorization; (2) the WebSocket upgrade handler never validates the HTTP Origin header. Attack vector: network-adjacent (requires the victim to visit an attacker-controlled website while the dashboard runs on localhost). Preconditions: default configuration (ROOM_SECRET unset, binding to 127.0.0.1), browser with same-origin WebSocket access. Attacker can: read workspace/session state via desktopCommand frames, inject arbitrary MCP server entries (including stdio commands) into cline_mcp_settings.json, control active Cline sessions with auto-approve enabled to execute commands, and exfiltrate credentials. A patch was merged on 2026-06-23 (PR #11724) that validates both Host and Origin headers against the configured dashboard origin/host.

Affected products

Cline Cline <= 3.0.24

Identifiers

CVE-2026-59723
GHSA-3cj3-hqcr-g934

Timeline

2026-06-23: disclosed: Advisory published
2026-06-23: patched: Fix merged in PR #11724 (commit d092709)

References

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