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

> Attackers can hijack cross-origin WebSocket connections in Cline Kanban servers, potentially leading to unauthorized actions or data modification.

- **Severity:** Critical 9.6 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 1 Jun 2026
- **Updated:** 4 Jun 2026
- **Also known as:** GHSA-5c57-rqjx-35g2

## What is CVE-2026-44211?

CVE-2026-44211 is a critical vulnerability in cline, published on 1 Jun 2026. An attacker can exploit it over the internet without logging in, 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. 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.

Weakness: CWE-306 (Missing Authentication for Critical Functionality), CWE-1385 (Missing Origin Validation in WebSockets)

## Which versions are affected by CVE-2026-44211?

2 open source packages ship an affected version, including cline. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `cline` | npm | All versions to 2.13.0 | None |
| `cline` | npm | All versions to 2.13.0 | None |

Products: Cline Cline.

## How do I fix CVE-2026-44211?

No fix has been published for CVE-2026-44211 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-44211 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-44211 exists.

## Other vulnerabilities in cline

- [CVE-2026-30313](https://insights.sbomify.com/CVE-2026-30313/): Command injection in n/a (critical 9.8)
- [CVE-2026-59723](https://insights.sbomify.com/CVE-2026-59723/): Cline: Cross-Origin WebSocket Hijacking in Cline Hub Dashboard (`/browser` endpoint) (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-44211 and fix it if it is affected.

What it is: CVE-2026-44211 is a critical vulnerability in cline, published on 1 Jun 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-44211 exists.

Affected packages and fixed versions:
- cline (npm): affected all versions up to 2.13.0; no fix listed
- cline (npm): affected all versions up to 2.13.0; no fix listed

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-44211/ (Markdown: https://insights.sbomify.com/CVE-2026-44211/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-44211
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-44211
- OSV: https://osv.dev/vulnerability/CVE-2026-44211

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-44211/
Summaries are generated and may contain mistakes; the official description above is the record.