CVE-2026-42086
OpenC3 COSMOS provides the functionality needed to send commands to and receive data from one or more embedded systems.
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| rubygems | openc3 | < 7.0.0 | 7.0.0 |
| pip | openc3 | >= 0, < 7.0.0 | 7.0.0 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Openc3 | Cosmos | before 7.0.0 Version 7.0.0 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-ffq5-qpvf-xq7x
- https://github.com/OpenC3/cosmos/security/advisories/GHSA-ffq5-qpvf-xq7x
- https://nvd.nist.gov/vuln/detail/CVE-2026-42086
- https://github.com/pypa/advisory-database/tree/main/vulns/openc3/PYSEC-2026-105.yaml
- https://github.com/rubysec/ruby-advisory-db/blob/master/gems/openc3/CVE-2026-42086.yml