---
id: CVE-2026-87994
title: >-
  Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI
  platform
summary: >-
  Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI
  platform. From 0.9.5 until 0.11.1, the channel branch of chat_completion in
  backend/open_webui/main.py checked channel write access and channel membership
  for a …
severity: medium
cvss: 4.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N'
cwe:
  - CWE-639
  - CWE-862
vendor: openwebui
product: open_webui
affected:
  - 'open_webui >= 0.9.5, < 0.11.1'
patched:
  - open_webui 0.11.1
published: '2026-09-09'
updated: '2026-09-16'
sourceUpdated: '2026-09-16T15:15:32.030'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-87994'
references:
  - url: >-
      https://github.com/open-webui/open-webui/commit/7d392bedc9c1aaecc94509a58e59186b614433dc
    label: security-advisories@github.com
  - url: 'https://github.com/open-webui/open-webui/pull/28631'
    label: security-advisories@github.com
  - url: 'https://github.com/open-webui/open-webui/releases/tag/v0.11.1'
    label: security-advisories@github.com
  - url: >-
      https://github.com/open-webui/open-webui/security/advisories/GHSA-fmqh-xp37-5hr8
    label: security-advisories@github.com
  - url: >-
      https://github.com/open-webui/open-webui/security/advisories/GHSA-fmqh-xp37-5hr8
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - cve.org
  - exploit-available
epss: 0.00372
epssPercentile: 0.28407
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-10T15:59:49.963213Z'
ingestedAt: '2026-09-11T14:42:19.871Z'
---

## Overview

Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.5 until 0.11.1, the channel branch of chat_completion in backend/open_webui/main.py checked channel write access and channel membership for a supplied message_id but did not verify that the calling user authored the targeted message. A channel member could use the chat completions endpoint to replace another member's message while preserving the victim as the stored author, altering the conversation record without gaining access to other channels. This issue is fixed in version 0.11.1.

## Affected

- `open_webui >= 0.9.5, < 0.11.1`

## Remediation

Upgrade past the affected range:

- `open_webui 0.11.1`