CVE-2026-42086

medium

Published 2026-04-22 · Modified 2026-05-20

💬 Discuss on Community ✚ Propose mitigation

CVSS v3

4.6

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

CVSS v4 NEW

—

not yet in upstream

VIR risk

4.6

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.

Predictions

Exploit likelihood

56%

Patch ETA

—

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.

✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

Package impact

Ecosystem	Package	Vulnerable	Fixed
RubyGems	openc3	`<>= 7.0.0`	`>= 7.0.0`
PyPI	openc3	`<7.0.0`	`7.0.0`
RubyGems	openc3	`<7.0.0`	`7.0.0`
RUBYGEMS	openc3	`< 7.0.0`	`7.0.0`

Application impact

Vendor	Product	Versions	Fixed
openc3	cosmos	`{"endExcluding":"7.0.0"}`	`7.0.0`
openc3	cosmos	`7.0.0`

References

CWEs

CWE-79

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.