CVE-2026-42085 — MEDIUM (4.3)

Q: How severe is CVE-2026-42085?

CVE-2026-42085 has been rated MEDIUM with a CVSS base score of 4.3/10. Review the CVSS metrics above for detailed severity breakdown.

Q: Is there a patch for CVE-2026-42085?

Check the references section above for vendor advisories and patch information. Affected products include: Openc3 Cosmos.

Vulnerability Description

OpenC3 COSMOS provides the functionality needed to send commands to and receive data from one or more embedded systems. Prior to versions 6.10.5 and 7.0.0-rc3, OpenC3 COSMOS contains a design flaw in the save_tool_config() function that allows saving tool configuration files at arbitrary locations inside the shared /plugins directory tree by supplying crafted configuration filenames. Although the implementation sufficiently mitigates standard path traversal attacks, by canonicalizing filename to an absolute path, all plugins share this same root directory. That enables users to create arbitrary file structures and overwrite existing configuration files within the shared /plugins directory. This issue has been patched in versions 6.10.5 and 7.0.0-rc3.

CVSS Score

4.3

MEDIUM

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

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

NONE

Integrity

LOW

Availability

NONE

Affected Products

Vendor	Product	Versions
Openc3	Cosmos	< 6.10.5

Related Weaknesses (CWE)

CWE-23

References

https://github.com/OpenC3/cosmos/commit/9957a9fa460c0c0cf5cdbf6a5931bbdd025246a5Patch
https://github.com/OpenC3/cosmos/commit/e6efccbd148ba0e3361c5891027f2373aa140d42Patch
https://github.com/OpenC3/cosmos/releases/tag/v6.10.5Release Notes
https://github.com/OpenC3/cosmos/releases/tag/v7.0.0-rc3Release Notes
https://github.com/OpenC3/cosmos/security/advisories/GHSA-4jvx-93h3-f45hExploitVendor Advisory
https://github.com/OpenC3/cosmos/security/advisories/GHSA-4jvx-93h3-f45hExploitVendor Advisory

FAQ

What is CVE-2026-42085?

CVE-2026-42085 is a vulnerability with a CVSS score of 4.3 (MEDIUM). OpenC3 COSMOS provides the functionality needed to send commands to and receive data from one or more embedded systems. Prior to versions 6.10.5 and 7.0.0-rc3, OpenC3 COSMOS contains a design flaw in ...

How severe is CVE-2026-42085?

CVE-2026-42085 has been rated MEDIUM with a CVSS base score of 4.3/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-42085?

Check the references section above for vendor advisories and patch information. Affected products include: Openc3 Cosmos.