OpenC3 COSMOS is Vulnerable to Self-XSS Through the Command Sender

TRUNG BÌNH 4.6CVE-2026-42086 · GHSA-ffq5-qpvf-xq7x · PYSEC-2026-105 · Công bố 04/05/2026 · cập nhật 26/10/2026

Tóm tắt nhanh

CVE-2026-42086 là lỗ hổng mức TRUNG BÌNH (CVSS 4.6) ảnh hưởng openc3, openc3, cosmos (openc3).
Xác suất bị khai thác trong 30 ngày tới (EPSS): 0.20%, cao hơn 9.8% các lỗ hổng khác.
Cách xử lý: cập nhật lên 7.0.0 hoặc mới hơn.

Gói / sản phẩm	Phiên bản bị ảnh hưởng	Phiên bản đã vá
openc3 PyPI	`< 7.0.0`	`7.0.0`
openc3 RubyGems	`< 7.0.0`	`7.0.0`
cosmos openc3	`= 7.0.0< 7.0.0`	`7.0.0`

Mô tả

Summary

The Command Sender UI uses an unsafe eval() function on array-like command parameters, which allows a user-supplied payload to execute in the browser when sending a command. This creates a self-XSS risk because an attacker can trigger their own script execution in the victim’s session, if allowed to influence the array parameter input, for example via phishing. If successful, an attacker may read or modify data in the authenticated browser context, including session tokens in local storage.

Details

The unsafe eval() usage on user-supplied ARRAY parameters happens in convertToValue method in CommandSender.vue

PoC

Using a drop-down form, choose any command that supports ARRAY parameters,
Inside square brackets “[…]” place a JavaScript code to be executed
Send command to CmdTlmServer using dedicated “Send” button
Observe JavaScript code being executed in the current browser session context

Below example uses INST ARYCMD to execute simple JavaScript code snippet alert(“XSS”). <img width="947" height="356" alt="image" src="https://github.com/user-attachments/assets/6fbdb6c9-616a-4268-bbb8-a8a1044437ad" />

Impact

Local JavaScript execution in the user's browser

Mô tả của NVD

OpenC3 COSMOS provides the functionality needed to send commands to and receive data from one or more embedded systems. Prior to version 7.0.0, the Command Sender UI uses an unsafe eval() function on array-like command parameters, which allows a user-supplied payload to execute in the browser when sending a command. This creates a self-XSS risk because an attacker can trigger their own script execution in the victim’s session, if allowed to influence the array parameter input, for example via phishing. If successful, an attacker may read or modify data in the authenticated browser context, including session tokens in local storage. This issue has been patched in version 7.0.0.