CVE-2026-44562: open-webui Unverified Ownership

Vulnerability summary

CVE-2026-44562 is a medium (CVSS 6.5) Unverified Ownership vulnerability in open-webui. EPSS estimates a 0.35% chance of exploitation in the next 30 days, higher than 27.6% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 15-05-2026
   PublishedVulnerability first disclosed.
2. 15-05-2026
   Last modifiedVulnerability information updated.

Description

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, the POST /api/v1/models/import endpoint allows users with the workspace.models_import permission to overwrite any existing model in the database, regardless of ownership. When an imported model's ID matches an existing model, the endpoint merges the attacker's payload over the existing model data and writes it to the database with no ownership or access grant validation. Additionally, filter_allowed_access_grants is never called, bypassing the access grant restrictions enforced on all other model mutation endpoints. This vulnerability is fixed in 0.9.0.

• CWE-283Unverified OwnershipThe product does not properly verify that a critical resource is owned by the proper entity.
• CWE-862Missing AuthorizationThe product does not perform an authorization check when an actor attempts to access a resource or perform an action.