CVE-2026-45396: open-webui

Vulnerability summary

CVE-2026-45396 is a medium (CVSS 5.4) vulnerability in open-webui. EPSS estimates a 0.36% chance of exploitation in the next 30 days, higher than 28.1% 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 0.9.5, the POST /api/v1/evaluations/feedback endpoint in Open WebUI v0.9.2 is vulnerable to mass assignment via FeedbackForm, which uses model_config = ConfigDict(extra='allow'). Due to an insecure dictionary merge order in insert_new_feedback(), an authenticated attacker can inject a user_id field in the request body that overwrites the server-derived value, creating feedback records attributed to any arbitrary user. This corrupts the model evaluation leaderboard (Elo ratings) and enables identity spoofing. This vulnerability is fixed in 0.9.5.

• CWE-915Improperly Controlled Modification of Dynamically-Determined Object AttributesThe product receives input from an upstream component that specifies multiple attributes, properties, or fields that are to be initialized or updated in an object, but it does not properly control which attributes can be modified.