CVE-2026-42088 OpenC3 COSMOS: Administrative Actions via the Script Runner Tool
Users with script execution permissions can bypass API checks to perform administrative actions, read secrets, and modify system settings.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-42088?
CVE-2026-42088 is a critical vulnerability in OpenC3 cosmos, published on 4 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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-rc3, the Script Runner widget allows users to execute Python and Ruby scripts directly from the openc3-COSMOS-script-runner-api container. Because all the docker containers share a network, users can execute specially crafted scripts to bypass the API permissions check and perform administrative actions, including reading and modifying data inside the Redis database, which can be used to read secrets and change COSMOS settings, as well as read and write to the buckets service, which holds configuration, log, and plugin files. These actions are normally only available from the Admin Console or with administrative privileges. Any user with permission to create and run scripts can connect to any service in the docker network. This issue has been patched in version 7.0.0-rc3.
Weakness: CWE-250
Which versions are affected by CVE-2026-42088?
3 open source packages ship an affected version, including openc3. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
openc3 PyPI | All versions | 7.0.0 |
openc3 RubyGems | All versions | 7.0.0-rc3 |
openc3 RubyGems | All versions | 7.0.0-rc3 |
Products include Openc3 Cosmos.
How do I fix CVE-2026-42088?
Upgrade openc3 to a fixed version for your release line: 7.0.0 or 7.0.0-rc3.
Is CVE-2026-42088 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-42088 exists.
Other vulnerabilities in OpenC3 cosmos
Sources
Also known as GHSA-2wvh-87g2-89hr, PYSEC-2026-2245.