CVE-2026-42085CWE-23

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

Medium · published May 4, 2026

CVSS v3.1
4.3
EPSS
0%
Percentile
34.3
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
4.3 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
CVSS v4.0
Not supplied
EPSS
0.00411 · 34.3th percentile
Weakness
CWE-23 · Relative Path Traversal
Published
2026-05-04T17:13Z
EPSS history
Timeline
  • 04 MAY 17:13Z
    OpenC3 COSMOS: Arbitrary write to plugins directory via path-traversed config filenames
    cvelistv5