CVE-2026-42088
OpenC3 COSMOS: Administrative Actions via the Script Runner Tool
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
9.6
OpenC3 COSMOS: Administrative Actions via the Script Runner Tool
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.
- Record
CVE-2026-42088- CVSS 3.1
- 9.6 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N - Weakness
- CWE-250
- Updated
- 2026-11-02
EUVDEUVD-2026-27065
9.6
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.
- Record
EUVD-2026-27065- CVSS 3.1
- 9.6 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-2wvh-87g2-89hr
9.6
OpenC3 COSMOS: Permissions Bypass Provides User Access to Unassigned Administrative Actions via Script Runner Tool
Vulnerability Type: Execution with Unnecessary Privileges Attack type: Authenticated remote Impact: Data disclosure/manipulation, privilege escalation Affected components: The following docker images: • Openc3inc/openc3-COSMOS-script-runner-api
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.
<img width="940" height="473" alt="image" src="https://github.com/user-attachments/assets/bf524163-127d-4349-999b-cefc53d4374d" />
Figure 1: Environment variables, including Redis credentials, found in the Script Runner container A Ruby script is used to expose the Redis username, password, hostname, and port. These credentials might also be found from the source code or through a brute-force attack.
<img width="940" height="507" alt="image" src="https://github.com/user-attachments/assets/6d3ccad4-949d-4eeb-a5f8-3aca48bbe815" />
Figure 2: A Python script is used to add data to Redis and retrieve the new data
A Python script is then used to create a new entry in the Redis database called openc3__settings_hacked with a key of store_url and a value of http://hacked.com.
<img width="940" height="70" alt="image" src="https://github.com/user-attachments/assets/fcef13be-5416-4627-9c95-617a24674ee0" />
Figure 3: The new data found in the Redis database
The new entry was successfully added to the Redis database, as is confirmed by using redis-cli.
The following example shows how an attacker might change the plugin store URL file that is stored in the config bucket.
<img width="940" height="640" alt="image" src="https://github.com/user-attachments/assets/681b4dd6-4b6e-4a91-8480-0c9fbff76ede" />
Figure 4: Uploading file to change the plugin store URL setting
<img width="940" height="189" alt="image" src="https://github.com/user-attachments/assets/630db0bb-217e-4205-be1d-e9891516b22f" />
Figure 5: The URL file was successfully changed
Steps To Reproduce
- Run the following Ruby code to find the Redis credentials:
puts `env | grep redis`
- Add the following Python script with the credentials to create a new entry and read it
import redis
import json
import time
r = redis.Redis(
host = 'openc3-redis',
port = 6379,
username = 'openc3',
password = 'openc3password',
decode_responses=True
)
# Save a setting
setting_data = {
'name': 'store_url',
'data': 'http://hacked.com',
'updated_at': time.time_ns()
}
r.hset('openc3__settings_hacked','store_url',json.dumps(setting_data))
print(r.hget('openc3__settings_hacked','store_url'))
Recommendations
• Limit the permissions of the script runner API to prevent lower level users from performing administrative actions
- Record
GHSA-2wvh-87g2-89hr- CVSS 3.1
- 9.6 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N - Weakness
- CWE-250
- Updated
- 2026-11-02
NVD
9.6
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.
- Record
CVE-2026-42088- CVSS 3.1
- 9.6 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N - CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-250
- Updated
- 2026-11-02
OSV
9.6
OpenC3 COSMOS: Administrative Actions via the Script Runner Tool
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.
- Record
CVE-2026-42088- CVSS 3.1
- 9.6 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N - Weakness
- CWE-250
- Updated
- 2026-11-02
OSVGHSA-2wvh-87g2-89hr
9.6
OpenC3 COSMOS: Permissions Bypass Provides User Access to Unassigned Administrative Actions via Script Runner Tool
Vulnerability Type: Execution with Unnecessary Privileges Attack type: Authenticated remote Impact: Data disclosure/manipulation, privilege escalation Affected components: The following docker images: • Openc3inc/openc3-COSMOS-script-runner-api
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.
<img width="940" height="473" alt="image" src="https://github.com/user-attachments/assets/bf524163-127d-4349-999b-cefc53d4374d" />
Figure 1: Environment variables, including Redis credentials, found in the Script Runner container A Ruby script is used to expose the Redis username, password, hostname, and port. These credentials might also be found from the source code or through a brute-force attack.
<img width="940" height="507" alt="image" src="https://github.com/user-attachments/assets/6d3ccad4-949d-4eeb-a5f8-3aca48bbe815" />
Figure 2: A Python script is used to add data to Redis and retrieve the new data
A Python script is then used to create a new entry in the Redis database called openc3__settings_hacked with a key of store_url and a value of http://hacked.com.
<img width="940" height="70" alt="image" src="https://github.com/user-attachments/assets/fcef13be-5416-4627-9c95-617a24674ee0" />
Figure 3: The new data found in the Redis database
The new entry was successfully added to the Redis database, as is confirmed by using redis-cli.
The following example shows how an attacker might change the plugin store URL file that is stored in the config bucket.
<img width="940" height="640" alt="image" src="https://github.com/user-attachments/assets/681b4dd6-4b6e-4a91-8480-0c9fbff76ede" />
Figure 4: Uploading file to change the plugin store URL setting
<img width="940" height="189" alt="image" src="https://github.com/user-attachments/assets/630db0bb-217e-4205-be1d-e9891516b22f" />
Figure 5: The URL file was successfully changed
Steps To Reproduce
- Run the following Ruby code to find the Redis credentials:
puts `env | grep redis`
- Add the following Python script with the credentials to create a new entry and read it
import redis
import json
import time
r = redis.Redis(
host = 'openc3-redis',
port = 6379,
username = 'openc3',
password = 'openc3password',
decode_responses=True
)
# Save a setting
setting_data = {
'name': 'store_url',
'data': 'http://hacked.com',
'updated_at': time.time_ns()
}
r.hset('openc3__settings_hacked','store_url',json.dumps(setting_data))
print(r.hget('openc3__settings_hacked','store_url'))
Recommendations
• Limit the permissions of the script runner API to prevent lower level users from performing administrative actions
- Record
GHSA-2wvh-87g2-89hr- CVSS 3.1
- 9.6 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N - Weakness
- CWE-250
- Updated
- 2026-11-02
OSVPYSEC-2026-2245
8.1
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.
- Record
PYSEC-2026-2245- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
openc3RubyGems |
before 7.0.0-rc3 | 7.0.0-rc3 |
openc3RubyGems |
before 7.0.0-rc3, plus listed versions 5.0.105.0.115.0.65.0.75.0.8 Show 45 moreShow less5.0.95.1.05.1.15.10.05.10.15.11.05.11.15.11.25.11.35.12.05.13.05.14.05.14.15.14.25.15.05.15.15.15.25.16.05.16.15.16.25.17.05.17.15.18.05.19.05.2.05.20.05.3.05.4.05.4.15.4.25.4.3.pre.beta05.5.05.5.0.pre.beta05.5.15.5.25.5.2.pre.beta05.6.05.6.15.7.05.7.25.8.05.8.15.9.05.9.16.0.0 |
7.0.0-rc3 |
openc3PyPI |
before 7.0.0, plus listed versions 0.1.05.10.05.10.15.11.05.11.1 Show 45 moreShow less5.11.25.11.35.12.05.13.05.14.05.14.15.14.25.15.05.15.15.15.25.16.05.16.15.16.25.17.05.17.15.18.05.19.05.20.05.9.2b06.0.06.0.16.0.26.1.06.10.06.10.16.10.26.10.36.10.46.10.56.10.66.2.06.2.16.3.06.4.06.4.16.4.26.5.06.5.16.6.06.7.06.8.06.8.16.9.06.9.16.9.2 |
7.0.0 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-42088 is a critical vulnerability (CVSS 9.6) in Openc3 Cosmos, published April 23, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.34%, the 27th percentile. Fixed in openc3 7.0.0-rc3.
References
github.com/OpenC3/cosmos/security/advisories/GHSA-2wvh-87g2-89hr
github.com/OpenC3/cosmos/releases/tag/v7.0.0
github.com/OpenC3/cosmos/releases/tag/v7.0.0-rc3
github.com/advisories/GHSA-2wvh-87g2-89hr
github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42088.json
nvd.nist.gov/vuln/detail/CVE-2026-42088
github.com/OpenC3/cosmos
Left out here: 27 versions. The JSON record has them.