CVE-2026-42085

OpenC3 COSMOS: Arbitrary write to plugins directory via path-traversed config filenames

Published May 4, 2026 CVSS 3.1 · 4.3 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-4jvx-93h3-f45h OpenC3 COSMOS allows arbitrary writes to plugins directory via path-traversed config filenames
History
Type Values Removed Values Added
CPEs cpe:2.3:a:openc3:cosmos:*:*:*:*:open_source:*:*:*
cpe:2.3:a:openc3:cosmos:7.0.0:rc1:*:*:open_source:*:*:*
cpe:2.3:a:openc3:cosmos:7.0.0:rc2:*:*:open_source:*:*:*
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Openc3
Openc3 cosmos
Vendors & Products Openc3
Openc3 cosmos
Type Values Removed Values Added
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.
Title OpenC3 COSMOS: Arbitrary write to plugins directory via path-traversed config filenames
Weaknesses CWE-23
References
Metrics cvssV3_1

{'score': 4.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
May 4, 2026, 6:47 PM
Reserved
Apr 23, 2026, 7:17 PM
Status
Analyzed
Published
May 4, 2026, 6:16 PM
Modified
Oct 26, 2026, 7:10 PM