Improper Auth Leading to Arbitrary Read-Write Access
February 6, 2024
Our third vulnerability is present in the fileserver component of the ClearML Server, which does not authenticate any requests to its endpoints, meaning an attacker can arbitrarily upload, delete, modify, or download files on the fileserver, even if the files belong to another user.
The ability to arbitrarily upload files means that the fileserver can be used to host any files, which could cause issues with space and storage but can also lead to more serious, potentially legal ramifications if the server is used to host malware or stolen or contraband data. To conduct an attack, an adversary only needs to know the address of the ClearML server, which can be obtained via a quick Shodan search (more on this later). Once they have a valid target, they can begin manipulating files on the fileserver, which, by default, is on port 8081, on the same IP address as the web server. It is important to note that when the contents of a file are modified directly in this manner, the web UI will not reflect these changes – the file size and checksum shown will remain the same. Therefore, an attacker could add malicious content to a previously verified file with no evidence of a change visible to regular users.
Related SAI Security Advisory
June 12, 2026
Post-Authentication RCE via update_collection
Any authenticated user with UPDATE_COLLECTION permission can achieve remote code execution by updating a collection's embedding function to reference a malicious HuggingFace model with trust_remote_code: true. The update_collection endpoint uses the same build_from_config() code path as CVE-2026-45829. Authentication runs before model loading, so this is not a pre-authentication issue, but the model instantiation itself is unguarded.
June 12, 2026
V1 API Tenant Isolation Bypass via Null Tenant/Database Context
All V1 collection-level endpoints pass None for tenant and database to the authorization layer, making tenant-scoped access control impossible through V1, regardless of which authorization provider is configured. V1 cannot be disabled. Combined with CVE-2026-45830, any authenticated user has unrestricted read/write access to any collection by UUID through V1 endpoints.