Skip to content
Fencer Intel
high 8.8

CVE-2026-77601 json

OpenC3 COSMOS: Authenticated OS command injection via the `pypi_url` setting

published last mo. modified last mo. also EUVD-2026-85563 , GHSA-vp3w-52v9-q57f

cvss
8.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 50%
public exploits
0
none known

Summary

OpenC3 COSMOS provides the functionality needed to send commands to and receive data from one or more embedded systems. From 5.12.0 until 7.3.0, an authenticated actor can write the pypi_url setting through set_setting at POST /openc3-api/api, then cause OpenC3::PluginModel.install_phase2 in openc3/lib/openc3/models/plugin_model.rb to interpolate the value into a shell command while installing a plugin with Python dependency metadata. Shell metacharacters in the setting are interpreted by the command shell, allowing arbitrary operating-system commands to run as the openc3 service user with access to Redis and bucket credentials. Open-source deployments permit any authenticated user to reach the affected operations, while Enterprise deployments require an administrator. This issue is fixed in version 7.3.0.

Patch / fix

  • rubygems openc3 7.3.0
  • openc3 cosmos 7.3.0

Is CVE-2026-77601 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
last mo.

Exploit prediction

0.63% chance of exploitation in the next 30 days, higher than 50% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • github.com https://github.com/OpenC3/cosmos/security/advisories/GHSA-vp3w-52v9-q57f referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
GitHub 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
rubygems openc3
>=5.12.0, <7.3.0
7.3.0

Affected products

  • OpenC3 cosmos

Classification

Weakness
  • CWE-78 Improper Neutralization of Special Elements used in an OS Command

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.