CVE-2026-42086CWE-79

OpenC3 COSMOS: Self-XSS in the Command Sender

Medium · published May 4, 2026

CVSS v3.1
4.6
EPSS
0%
Percentile
20.0
In the wild
Unconfirmed
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.

The record
Technical detail
CVSS v3.1
4.6 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N
CVSS v4.0
Not supplied
EPSS
0.00286 · 20.0th percentile
Weakness
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Published
2026-05-04T17:15Z
EPSS history
Timeline
  • 04 MAY 17:15Z
    OpenC3 COSMOS: Self-XSS in the Command Sender
    cvelistv5