Max-severity vulnerability in ChromaDB allows unauthenticated remote code execution

A critical vulnerability in the Python FastAPI version of the ChromaDB project, tracked as CVE-2026-45829, allows unauthenticated attackers to execute arbitrary code on exposed servers. This flaw, discovered by HiddenLayer, has been assigned the maximum CVSS score of 10. ChromaDB is an open-source vector database and AI retrieval backend widely used in agentic AI applications, as reported by Bleeping Computer.

The vulnerability affects the Python API server logic within the PyPI package, which sees nearly 14 million monthly downloads. Attackers can exploit this by sending a crafted request to an authenticated API endpoint. This request embeds model settings before the authentication check is performed, allowing the attacker to force ChromaDB to load and execute a malicious model from platforms like Hugging Face. The authentication check occurs too late, after the malicious code has already run. The flaw was introduced in ChromaDB version 1.0.0 and was present in version 1.5.8. While version 1.5.9 was released, it remains unclear if the vulnerability is patched.

Approximately 73% of internet-exposed ChromaDB instances are believed to be running a vulnerable version. Mitigation strategies include using the Rust frontend, avoiding public exposure of the Python server, restricting network access to the API port, and scanning ML model artifacts before runtime.

Source: Bleeping Computer