CVE-2026-45396

MEDIUM

Open WebUI: Mass Assignment via FeedbackForm extra=allow Allows Feedback User ID Spoofing and Evaluation Data Manipulation

Title source: cna

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.

References (1)

Core 1

Core References

X_Refsource_Confirm x_refsource_confirm

https://github.com/open-webui/open-webui/security/advisories/GHSA-rjmp-vjf2-qf4g

Scores

CVSS v3 5.4

EPSS 0.0003

EPSS Percentile 9.5%

Attack Vector NETWORK

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L

CISA SSVC

Vulnrichment

Exploitation poc

Automatable no

Technical Impact partial

Details

CWE

CWE-915

Status published

Products (3)

open-webui/open-webui < 0.9.5

openwebui/open_webui < 0.9.5

pypi/open-webui 0 - 0.9.5PyPI

Published May 15, 2026

Tracked Since May 16, 2026