Mass Assignment Vulnerability in Open WebUI Affects Self-Hosted AI Platform
CVE-2026-45396

5.4MEDIUM

Key Information:

Vendor

Open-webui

Status
Open-webui
Vendor
CVE Published:
15 May 2026

What is CVE-2026-45396?

Open WebUI, a self-hosted AI platform, has a vulnerability in the POST /api/v1/evaluations/feedback endpoint prior to version 0.9.5. This flaw allows an authenticated attacker to exploit the FeedbackForm due to an insecure dictionary merge order in the insert_new_feedback() function. By injecting a user_id field in the request body, the attacker can overwrite server-derived values, resulting in feedback attributed to arbitrary users. This manipulation undermines the integrity of the model evaluation leaderboard and poses risks of identity spoofing. The issue was resolved in version 0.9.5.

Affected Version(s)

open-webui < 0.9.5

References

https://github.com/open-webui/open-webui/security/advisor...
x_refsource_CONFIRM

CVSS V3.1

Score:
5.4
Severity:
MEDIUM
Confidentiality:
None
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

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