CVE-2026-28788

HIGH EPSS 85.0%
Published Mar 27, 20263mo ago · Modified Jun 17, 20261w ago
7.1 CVSS 3.1
High
Find Similar
Published Mar 27, 2026 3mo ago
Last Modified Jun 17, 2026 1w ago

Description

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to version 0.8.6, any authenticated user can overwrite any file's content by ID through the `POST /api/v1/retrieval/process/files/batch` endpoint. The endpoint performs no ownership check, so a regular user with read access to a shared knowledge base can obtain file UUIDs via `GET /api/v1/knowledge/{id}/files` and then overwrite those files, escalating from read to write. The overwritten content is served to the LLM via RAG, meaning the attacker controls what the model tells other users. Version 0.8.6 patches the issue.

CVSS Details

Base Score
7.1
Exploitability
2.8
Impact
4.2
Vector string
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L
Attack Vector Network
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality None
Integrity High
Availability Low

Threat Intelligence

EPSS Exploit Probability
85.0% percentile
Exploit & Patch Status
Public Exploit Known
No Patch Available

Weaknesses 1

CWE-639

Affected Products 1

VendorProductVersionRange
openwebuiopen_webui* <0.8.6

References 1

  • github.com https://github.com/open-webui/open-webui/security/advisories/GHSA-jjp7-g2jw-wh3j
    ExploitVendor Advisory

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.