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

中 4.6CVE-2026-42086 · GHSA-ffq5-qpvf-xq7x · PYSEC-2026-105 · 04/05/2026 公開 · 26/10/2026 更新

要点

CVE-2026-42086 は openc3, openc3, cosmos (openc3) に影響する深刻度「中」 (CVSS 4.6) の脆弱性です。
今後30日間に悪用される確率（EPSS）：0.20%（全脆弱性の 9.8% より高い）。
対処：7.0.0 以降に更新してください。

パッケージ	影響を受けるバージョン	修正済みバージョン
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`

概要

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

NVD の説明

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.