CVE-2026-42086

4.6 MEDIUM 0.2% exploit odds Fix listed XSS Browser & mail

What it is

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.

At a glance

Exploitability: Can be exploited over the network with a low-privilege account, but needs a user to act. Limited direct impact.
Exploit odds: 0.2% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2026-05-04 18:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-10-26 19:10 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 0.2% in the next 30 days (EPSS).
Severity: 4.6 MEDIUM (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2026-05-04 18:16 UTC
Last modified: 2026-10-26 19:10 UTC
Exploit probability: 0.2% · EPSS, next 30 days
Weakness: CWE-79 · Cross-site scripting
Record status: Analyzed

Affected

openc3 Cosmos < 7.0.0
openc3 Cosmos 7.0.0

Attack profile CVSS 3.1 · 4.6

Attack vector: Network
Complexity: Low
Privileges needed: Low
User interaction: Required
Scope: Unchanged
Confidentiality: Low
Integrity: Low
Availability: None

Raw vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N

Is it in your code?

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Read https://cve-list.com/agent/cve/CVE-2026-42086.md and follow it. Check whether this project is affected by CVE-2026-42086. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record