critical CVSS 9.6

CVE-2026-42088·Docker vulnerability

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.

Severity
critical
Software
Docker
Fixed in
7.0.0
Published
2026-05-04

Affected versions

Until: 7.0.0

Fixed in: 7.0.0

How to fix this CVE

Upgrade Docker to version 7.0.0 or later to patch the Script Runner privilege escalation vulnerability that allows unauthorized network access to backend services. Users running OpenC3 COSMOS should prioritize this update as any script creator can now bypass API permissions and access sensitive systems like Redis and bucket storage. Apply the update immediately across all Docker hosts running affected versions.

sudo dnf update docker-ce

Defensia detects this vulnerability

How to check if you are affected

  1. Check Docker version: docker --version — verify it shows 7.0.0 or higher
  2. Confirm OpenC3 COSMOS image version: docker images | grep cosmos — ensure image tags reference version 7.0.0-rc3 or later
  3. Review Script Runner container logs for suspicious script execution: docker logs <script-runner-container-id> | grep -i 'redis\|bucket\|administrative'
  4. Verify fixed version is running: docker inspect <container-id> | grep -i 'version\|image' and confirm it reflects the patched release

FAQ

What is CVE-2026-42088?

CVE-2026-42088 is a critical privilege escalation vulnerability in Docker/OpenC3 COSMOS where the Script Runner widget fails to enforce API permission boundaries. This allows any user with script execution privileges to connect directly to backend services (Redis, bucket storage) on the shared container network and perform administrative actions like reading secrets and modifying configuration files.

Is CVE-2026-42088 being actively exploited?

No, CVE-2026-42088 is not currently listed in the CISA Known Exploited Vulnerabilities (KEV) catalog and no public exploits are available. However, the low attack complexity and network accessibility make it a high-priority target for future exploitation.

What versions of Docker are affected by CVE-2026-42088?

All Docker versions prior to 7.0.0 are affected. The vulnerability was introduced in earlier releases and is patched starting with version 7.0.0 and release candidate 7.0.0-rc3.

How do I check if my server is vulnerable to CVE-2026-42088?

Run `docker --version` and compare the output to 7.0.0. If your version is lower, you are vulnerable. Additionally, check `docker images | grep cosmos` to verify OpenC3 COSMOS component versions are below 7.0.0.

Does Defensia detect CVE-2026-42088?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If Docker is installed on a monitored server, CVE-2026-42088 will appear in your dashboard with remediation steps.

Related Docker CVEs

CVE-2026-40281CVSS 10Gotenberg is a Docker-powered stateless API for PDF files. In versions 8.30.1 and earlier, the metadata write endpoint validates metadata keys for control characters but leaves metadata values unsanitized. A newline character in a metadata value splits the ExifTool stdin line into two separate arguments, allowing injection of arbitrary ExifTool pseudo-tags such as -FileName, -Directory, -SymLink, and -HardLink. This is a bypass of the incomplete key-sanitization fix introduced in v8.30.1. An unauthenticated attacker can rename or move any PDF being processed to an arbitrary path in the container filesystem, overwrite arbitrary files, or create symlinks and hard links at arbitrary paths.
CVE-2026-57572CVSS 10Crawl4AI is an open-source LLM-friendly web crawler and scraper. Prior to 0.9.0, the Docker API server accepted request-supplied browser_config.extra_args, which flowed into Chromium's launch arguments. An attacker could inject Chromium switches that replace a child-process launch command together with --no-zygote, causing Chromium to fork or exec an attacker-controlled command as the container's runtime user. The Docker API is unauthenticated by default, so a single request yields arbitrary command execution. This issue is fixed in version 0.9.0.
CVE-2026-53576CVSS 10Kestra is an open-source, event-driven orchestration platform. Prior to 1.0.45 and 1.3.21, the authentication filter for the REST API (@Filter("/api/v1/**")) treats any request whose path ends in /configs as the public instance-config endpoint and forwards it without a credential check. kestra addresses its resources by URL path segments that the caller chooses (/api/v1/{tenant}/flows/{namespace}, /api/v1/{tenant}/executions/{namespace}/{id}, /api/v1/{tenant}/namespaces/{namespace}/kv/{key}). An anonymous caller picks the literal configs as the final segment, and the request bypasses Basic-Auth entirely. Because the bypass reaches the flow-create and execution-trigger routes, an unauthenticated caller creates a flow containing a Shell or Process task and runs it. The task executes as root inside the kestra container. The official docker-compose.yml mounts /var/run/docker.sock, so root in the container reaches the host Docker daemon. This vulnerability is fixed in 1.0.45 and 1.3.21.
CVE-2026-42298CVSS 10Postiz is an AI social media scheduling tool. Prior to commit da44801, a "Pwn Request" vulnerability in the Build and Publish PR Docker Image workflow (.github/workflows/pr-docker-build.yml) allows any unauthenticated user to execute arbitrary code during the Docker build process and exfiltrate a highly privileged GITHUB_TOKEN (write-all permissions). This can be achieved simply by opening a Pull Request from a fork with a maliciously modified Dockerfile.dev. This issue has been patched via commit da44801.
CVE-2026-26216CVSS 10Crawl4AI versions prior to 0.8.0 contain a remote code execution vulnerability in the Docker API deployment. The /crawl endpoint accepts a hooks parameter containing Python code that is executed using exec(). The __import__ builtin was included in the allowed builtins, allowing unauthenticated remote attackers to import arbitrary modules and execute system commands. Successful exploitation allows full server compromise, including arbitrary command execution, file read and write access, sensitive data exfiltration, and lateral movement within internal networks.

References

Track CVEs across your fleet automatically

Defensia scans your Linux servers and tells you exactly which ones are running vulnerable versions — including CVE-2026-42088. Free for 1 server.

Get started free