CVE-2026-42086
Analyzed Analyzed - Analysis Complete
Self-XSS in OpenC3 COSMOS Command Sender UI

Publication date: 2026-05-04

Last updated on: 2026-05-08

Assigner: GitHub, Inc.

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 Scores
EPSS Scores
Probability:
Percentile:
Meta Information
Published
2026-05-04
Last Modified
2026-05-08
Generated
2026-06-16
AI Q&A
2026-05-05
EPSS Evaluated
2026-06-15
NVD
CVE-2026-42086
Affected Vendors & Products
Showing 4 associated CPEs
Vendor Product Version / Range
openc3 cosmos to 7.0.0 (exc)
openc3 cosmos 7.0.0
openc3 cosmos 7.0.0
openc3 cosmos 7.0.0
Helpful Resources
Exploitability
CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-79 The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
Attack-Flow Graph
AI Quick Actions
Instant insights powered by AI
Executive Summary

This vulnerability exists in OpenC3 COSMOS versions prior to 7.0.0, where the Command Sender UI uses an unsafe eval() function on array-like command parameters. This allows a user-supplied payload to execute in the browser when sending a command, creating a self-XSS (Cross-Site Scripting) risk. An attacker can trigger their own script execution in the victim’s browser session if they can influence the array parameter input, for example through phishing.

If exploited, the attacker may read or modify data within the authenticated browser context, including sensitive information such as session tokens stored in local storage. This vulnerability was fixed in version 7.0.0.

Impact Analysis

If this vulnerability is exploited, an attacker can execute malicious scripts in your browser session, potentially allowing them to read or modify sensitive data such as session tokens stored locally. This can lead to unauthorized access to your account or data within the application.

The attack requires the attacker to influence the array parameter input, which could be done via phishing or other social engineering techniques. The impact includes loss of confidentiality and integrity of data within the authenticated session.

Mitigation Strategies

To mitigate this vulnerability, upgrade OpenC3 COSMOS to version 7.0.0 or later, where the unsafe eval() usage has been patched.

Additionally, be cautious of phishing attempts that could allow attackers to influence array parameter inputs and trigger self-XSS.

Compliance Impact

The vulnerability allows an attacker to execute scripts in the victim's browser session, potentially reading or modifying data including session tokens stored locally. This could lead to unauthorized access to sensitive information.

Such unauthorized access and potential data exposure may impact compliance with standards and regulations like GDPR and HIPAA, which require protection of personal and sensitive data against unauthorized access.

However, the provided information does not explicitly discuss the direct impact on compliance with these standards.

Chat Assistant
Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-42086. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70
EPSS Chart