CVE-2026-45830: A lack of authorization validation in version 0

Synopsis

An authorization bypass vulnerability in ChromaDB (version 0.4.17 and later) allows any authenticated user to read, write, update, or delete data across all tenant collections without restriction. The flaw is reachable over the network and requires only a low-privilege account, meaning an attacker with standard credentials can cross tenant boundaries freely. Successful exploitation gives full access to other tenants' stored data and the ability to tamper with or destroy it. HarborGuard is tracking the advisory for patch availability, as no fix version has been published yet.

HarborGuard Coverage

Exploit Conditions

• Network reachabilityRequired

  The vulnerable ChromaDB service must be reachable over the network; the attacker sends crafted API requests directly to it.

• AuthenticationRequired

  A low-privilege account is sufficient; any valid ChromaDB user credential satisfies this requirement, but some form of login is necessary.

• Victim interactionNot required

  No user interaction is needed; the attacker operates entirely through their own authenticated session without involving another user.

• Attack complexityDetail

  Base exploitation is condition-free and reliable (AC:L), though an attack trigger prerequisite (AT:P) means certain environmental or timing conditions must align for the cross-tenant access to succeed.

Blast Radius

• Reads all stored vectors, metadata, and documents in any other tenant's ChromaDB collections, exposing data the attacker has no legitimate access to.
• Writes or overwrites records in other tenants' collections, allowing poisoning of vector embeddings or injection of malicious data.
• Updates or deletes arbitrary collection entries across all tenants, enabling permanent data destruction or silent corruption of production datasets.
• Achieves equivalent impact on systems connected to ChromaDB (SC:H, SI:H) that consume its data, as tampered or exfiltrated embeddings propagate downstream.