---
id: CVE-2026-77394
title: >-
  OpenC3 COSMOS provides the functionality needed to send commands to and
  receive data from one or more embedded systems
summary: >-
  OpenC3 COSMOS provides the functionality needed to send commands to and
  receive data from one or more embedded systems. From 5.0.6 until 7.3.0, an
  authenticated actor with system_set permission can store a shared screen
  through POST /ope…
severity: high
cvss: 7.6
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N'
cwe:
  - CWE-79
vendor: OpenC3
product: cosmos
affected:
  - 'cosmos >= 5.0.6, < 7.3.0'
published: '2026-09-23'
updated: '2026-09-23'
sourceUpdated: '2026-09-23T20:17:15.660'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-77394'
references:
  - url: >-
      https://github.com/OpenC3/cosmos/commit/10371f8f410b9ad588f98dfa3befaaacb6587cd3
    label: security-advisories@github.com
  - url: 'https://github.com/OpenC3/cosmos/pull/3560'
    label: security-advisories@github.com
  - url: 'https://github.com/OpenC3/cosmos/releases/tag/v7.3.0'
    label: security-advisories@github.com
  - url: 'https://github.com/OpenC3/cosmos/security/advisories/GHSA-gvf2-2rh5-mpgf'
    label: security-advisories@github.com
  - url: 'https://github.com/OpenC3/cosmos/security/advisories/GHSA-gvf2-2rh5-mpgf'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: 'https://github.com/advisories/GHSA-gvf2-2rh5-mpgf'
tags:
  - nvd
  - cve.org
  - exploit-available
  - ghsa
  - npm
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-23T19:27:36.468261Z'
ingestedAt: '2026-09-23T19:31:04.466Z'
aliases:
  - GHSA-gvf2-2rh5-mpgf
ecosystem: npm
patched:
  - '@openc3/vue-common 7.3.0'
epss: 0.0039
epssPercentile: 0.30232
---

## Overview

OpenC3 COSMOS provides the functionality needed to send commands to and receive data from one or more embedded systems. From 5.0.6 until 7.3.0, an authenticated actor with system_set permission can store a shared screen through POST /openc3-api/screen whose BUTTON widget action is evaluated by openc3-cosmos-init/plugins/packages/openc3-vue-common/src/widgets/ButtonWidget.vue in another operator's browser session when the button is activated. The stored script runs in the COSMOS origin and can read localStorage.openc3Token, allowing theft of the victim's bearer token, account takeover, and actions with the victim's privileges. The permissive content security policy contributes to execution but is not the primary root cause. This issue is fixed in version 7.3.0.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-77394)

Affected packages:

- `@openc3/vue-common >= 5.0.6, <= 7.2.1`

Patched in:

- `@openc3/vue-common 7.3.0`

Source: https://github.com/advisories/GHSA-gvf2-2rh5-mpgf