Vulnerability · Published Jul 8, 2026 · Assigned by GitHub_M

CVE-2026-59723Cline: Cross-Origin WebSocket Hijacking in Cline Hub Dashboard (`/browser` endpoint)

High 8.8

In plain English

A high-severity security flaw in cline from cline. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 16% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.8High

Exploit odds (30 days)0.2%top 83.7% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	cline	3.0.30	GHSA-3cj3-hqcr-g934

Affected products (as reported)

Vendor	Product	Versions
cline	cline	< 3.0.30

Weakness: CWE-346 · Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

References

https://github.com/cline/cline/security/advisories/GHSA-3cj3-hqcr-g934 x_refsource_CONFIRM
https://github.com/cline/cline/pull/11724 x_refsource_MISC
https://github.com/cline/cline/commit/d09270940f5746f288cfc4a5039b46a2f4d5d01e x_refsource_MISC
https://github.com/cline/cline/releases/tag/cli-v3.0.30 x_refsource_MISC