---
title: "CVE-2026-44211: Cline Kanban Server has a Cross-Origin WebSocket Hijacking Vulnerability"
url: https://erroneo.us/security/cve/CVE-2026-44211/
description: "CVE-2026-44211 (cline (npm)): Cline is an autonomous coding agent as an SDK, IDE extension, or CLI assistant. In versions 2.13.0 and prior, there is a…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-06-01
date_modified: 2026-06-09
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-44211"
kev: false
cvss: 9.6
epss: 0.00207
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-44211: Cline Kanban Server has a Cross-Origin WebSocket Hijacking Vulnerability

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Not in CISA KEV , but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 0.2% , percentile 10: FIRST’s model estimates a 0.2% chance of exploitation activity in the next 30 days, higher than 10% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Needs a user to click or open something. Phishing makes that realistic, but it is not wormable.
- Only applies if your dependency tree includes cline (npm) <= 2.13.0, no fixed version listed . Check your lockfile, including transitive dependencies.

## What it is

Cline is an autonomous coding agent as an SDK, IDE extension, or CLI assistant. In versions 2.13.0 and prior, there is a cross-origin WebSocket hijack vulnerability in Cline Kanban servers. At time of publication, there are no publicly available patches.

## Affected packages

- npm `cline` <= 2.13.0 → fixed: none listed

## Affected products (CVE record)

- cline cline: <= 2.13.0

## Severity

- GitHub_M CVSS 3.1: 9.6 `CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H`
- GitHub CVSS 3.1: 9.6 `CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.21% probability of exploitation activity in the next 30 days; percentile 10.

## Sources

- [GitHub Advisory GHSA-5c57-rqjx-35g2](https://github.com/advisories/GHSA-5c57-rqjx-35g2)
- [CVE.org record CVE-2026-44211](https://www.cve.org/CVERecord?id=CVE-2026-44211)
- [NVD entry CVE-2026-44211](https://nvd.nist.gov/vuln/detail/CVE-2026-44211)
- [github.com](https://github.com/cline/cline/security/advisories/GHSA-5c57-rqjx-35g2)

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Source page: https://erroneo.us/security/cve/CVE-2026-44211/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt