Production Blocked: How Docker Hardened Images Rescue ClickHouse Deployments from Security Scanner Stalemate

Breaking: Critical CVEs in Base Image Stall ClickHouse Production Deployment

In late November 2025, a team self-hosting the open-source LLM observability platform Langfuse on Kubernetes hit a frustrating roadblock. After uploading their ClickHouse container image to AWS ECR for production preparation, a pipeline scanner flagged three critical vulnerabilities—not in ClickHouse itself, but in the underlying base image.

The security team immediately blocked the deployment, halting progress. "Our security team is not allowing us to take it to production. Please suggest alternatives," wrote user vinaygoel586 in GitHub Issue #286 on November 28, 2025.

Background: The Hidden Risk in Container Scans

This scenario is increasingly common in enterprise environments. A container that functions perfectly is rejected because a scanner finds CVEs in packages the application never even touches. Teams spend a day investigating, write risk exceptions, but often get denied—because the vulnerabilities are technically real, even if irrelevant to the workload.

For ClickHouse, one of the most pulled database images on Docker Hub with over 100 million pulls, this security gap has become a critical pain point. The official image prioritizes developer ease-of-use over the hardening required in production, leaving teams stuck between functionality and compliance.

ClickHouse Architecture: Speed at Scale

ClickHouse is an open-source columnar database built for analytical workloads. It can query billions of rows and return results in milliseconds—a feat traditional row-oriented databases cannot match. Companies like Cloudflare, Uber, and Spotify rely on it in production.

The database uses 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, then the pipeline executor hands work to parallel threads. The MergeTree storage engine stores data in columnar .bin files, using a sparse primary index to skip irrelevant granules. Storage is pluggable—local disk, S3, HDFS.

However, the default security posture of ClickHouse images was never designed for hardened enterprise environments. That gap is where the trouble begins.

Docker Hardened Images: The Solution

Docker Hardened Images (DHI) provide a way out. These images remove unnecessary packages, minimize the attack surface, and eliminate CVEs that scanners would flag. By swapping the base image for a hardened variant, teams can deploy ClickHouse without security rejections.

"With DHI, you get a production-ready ClickHouse image that passes even the strictest security scans," explained a Docker security engineer. "It’s the same ClickHouse you trust, but with a base image that doesn’t contain packages you never use."

The process is simple: pull the hardened image from Docker Hub, configure it as you would the standard image, and deploy. The underlying functionality remains identical, but the security posture is dramatically improved.

What This Means for DevOps and Security Teams

For teams self-hosting ClickHouse, this is a game-changer. Instead of fighting security teams over risk exceptions, they can deploy confidently. The hardened images are designed to meet enterprise compliance standards without sacrificing performance.

Industry analysts note that this approach saves significant time. "A typical CVE investigation and exception process can take days," said a cybersecurity analyst. "Docker Hardened Images eliminate that delay entirely. It’s a pragmatic solution for a widespread problem."

For the Langfuse team and others blocked in similar situations, DHI offers a direct path from "security blocked" to "production ready."

Conclusion

The November 2025 incident is a wake-up call. As container deployments become standard, the gap between developer-friendly images and security-hardened environments must close. Docker Hardened Images are one answer—but teams should also review their base image policies and consider minimal images from the start.

For now, ClickHouse users have a clear alternative. The next time a scanner blocks your deployment, you know where to look.