Vulnerability Description
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.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Openc3 | Cosmos | < 7.0.0 |
Related Weaknesses (CWE)
References
- https://github.com/OpenC3/cosmos/security/advisories/GHSA-ffq5-qpvf-xq7xExploitVendor Advisory
- https://github.com/OpenC3/cosmos/security/advisories/GHSA-ffq5-qpvf-xq7xExploitVendor Advisory
FAQ
What is CVE-2026-42086?
CVE-2026-42086 is a vulnerability with a CVSS score of 4.6 (MEDIUM). 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 ...
How severe is CVE-2026-42086?
CVE-2026-42086 has been rated MEDIUM with a CVSS base score of 4.6/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-42086?
Check the references section above for vendor advisories and patch information. Affected products include: Openc3 Cosmos.