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GHSA-ffq5-qpvf-xq7x

MEDIUM

GHSA-ffq5-qpvf-xq7x is a medium-severity (CVSS 4.6) Cross-site Scripting (XSS) vulnerability in openc3. O3 Security confirms whether GHSA-ffq5-qpvf-xq7x is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

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

Also known asCVE-2026-42086PYSEC-2026-105
Published
Apr 22, 2026
Updated
May 29, 2026
Affected
2 pkgs
Patched
2 / 2
Exploits
None indexed

Blast Radius

2 pkgs affected
🐍openc3💎openc3

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI, RubyGems packages — download data is not available via public APIs for these ecosystems.

Description

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

  1. Using a drop-down form, choose any command that supports ARRAY parameters,
  2. Inside square brackets “[…]” place a JavaScript code to be executed
  3. Send command to CmdTlmServer using dedicated “Send” button
  4. 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" />

<img width="942" height="545" alt="image" src="https://github.com/user-attachments/assets/4df24353-aea0-4aa0-adcf-b7c7e387dc83" />

Impact

Local JavaScript execution in the user's browser

Affected Packages

2 total 2 fixed
EcosystemPackageVulnerable rangeFix
🐍PyPIopenc3all versions7.0.0
💎RubyGemsopenc3all versions7.0.0

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for openc3. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

  2. Fix

    Update openc3 to 7.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-ffq5-qpvf-xq7x is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 pinpoints whether GHSA-ffq5-qpvf-xq7x is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-ffq5-qpvf-xq7x. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### 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 `conv
O3 Security · Impact-Aware SCA

Is GHSA-ffq5-qpvf-xq7x in your dependencies?

O3 detects GHSA-ffq5-qpvf-xq7x across PyPI, RubyGems dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.