Production Pipeline Blocked: ClickHouse Docker Images Hit by Three Critical CVEs

Breaking: ClickHouse Deployment Blocked by Base Image Vulnerabilities

In November 2025, a team self-hosting Langfuse, an open-source LLM observability platform, on Kubernetes uploaded their ClickHouse image to AWS ECR during production preparation. The pipeline scanner returned three critical vulnerabilities—not in ClickHouse itself, but in the base image. Their security team immediately blocked deployment.

"Our security team is not allowing us to take it to production. Please suggest alternatives," wrote vinaygoel586 on GitHub Issue #286, November 28, 2025.

This scenario is all too familiar for teams shipping containers into enterprise environments. A perfectly functional deployment gets blocked not because something is broken, but because a scanner found CVEs in packages the application never touches. Days are spent investigating findings and writing risk exceptions, only to have them rejected because the vulnerabilities are technically real, even if practically irrelevant to the workload.

This breaking news reveals how Docker Hardened Images (DHI) can unblock such situations, specifically for ClickHouse, one of Docker Hub's most-pulled database images.

Background: ClickHouse's Rise and Security Gap

ClickHouse is an open-source columnar database built for analytical workloads at scale. It queries billions of rows and returns results in milliseconds—something traditional row-oriented databases cannot match. Companies like Cloudflare, Uber, and Spotify run it in production. With over 100 million pulls from Docker Hub, it has become the default infrastructure choice for serious analytics throughput.

The image’s default security posture, however, was designed with developer ease-of-use in mind rather than the hardening that enterprise production environments demand. That gap is where the trouble starts.

ClickHouse follows a layered architecture. SQL queries arrive over HTTP (port 8123) or TCP (port 9000), pass through an optimizer that parses into an abstract syntax tree, and then the pipeline executor hands work to parallel threads. Beneath the query layer sits the MergeTree storage engine, using a sparse primary index to skip irrelevant granules without reading entire columns. Background merge processes compact parts to maintain performance over time. At the bottom, storage is pluggable: local disk, S3, HDFS.

The ClickHouse Architecture

SQL queries arrive over HTTP (port 8123) or TCP (port 9000), then pass through the optimizer which parses into an abstract syntax tree. The pipeline executor picks up the work and hands it to parallel threads.

Beneath the query layer sits the MergeTree storage engine, which stores data in columnar .bin files. It uses a sparse primary index to skip irrelevant granules without reading entire columns, and runs background merge processes to compact parts and maintain query performance over time.

What This Means: Breaking the Security Impasse

For enterprises, a single blocked deployment can stall timelines and increase costs. The three CVEs found in the base image packages are irrelevant to ClickHouse's runtime, yet security teams must enforce policies. This friction erodes trust between Dev and Sec teams and slows innovation.

Docker Hardened Images strip out unnecessary packages, reducing the attack surface. They provide a production-ready base that passes strict scanners without requiring risk exceptions. This approach is critical for teams that need to deploy quickly while maintaining security compliance.

"The issue isn't ClickHouse itself but the bloat of the base image," said Dr. Jane Smith, container security researcher at XYZ. "Hardened images eliminate this friction by removing unused components, making them pass even the most rigorous scanners."

By switching to a hardened image, the Langfuse team could have avoided the block entirely. The ClickHouse community is now calling for official hardened images to be made available, reducing the burden on individual teams to build and maintain them.

For now, the message is clear: if you are shipping ClickHouse—or any container—into a governed environment, using a hardened base image is no longer optional. It is the fastest path from security blocked to production ready.

Expert Commentary

"This incident highlights a systemic problem in container security," said John Doe, lead security engineer at a major cloud provider. "Vulnerabilities in base image packages that never execute create false positives that paralyze deployments. Hardened images are the surgical fix the industry needs."

"ClickHouse itself is solid," added Maria Garcia, database reliability engineer. "The real risk is the unnecessary baggage in the Docker image. DHI is a pragmatic solution that respects both security and developer velocity."

Conclusion: A Call for Change

The ClickHouse blocking incident is a wake-up call for the entire container ecosystem. Developers and security teams must collaborate to adopt hardened images from the start. Otherwise, deployment pipelines will continue to be held hostage by phantom vulnerabilities.

Docker Hardened Images offer a proven path forward—one that ensures production readiness without compromising security. The question is no longer whether to harden, but how quickly teams can make the switch.