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TI-2026-22983 Aliases CVE-2026-28788GHSA-jjp7-g2jw-wh3j

Open WebUI's process_files_batch() endpoint missing ownership check, allows unauthorized file overwrite

Priority MEDIUM 64CWE-639Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
None · High · Low
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-639.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.02969 87th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed open-webui (open-webui): 0.8.6open-webui (PyPI): 0.8.6

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
open-webuiopen-webuibefore 0.8.60.8.6Patch availableCNA
—open-webui (PyPI)before 0.8.60.8.6Patch availableGHSA-jjp7-g2jw-wh3j
  • open-webui Vendoropen-webui Affected before 0.8.6 Fixed in 0.8.6 Patch available CNA
  • open-webui (PyPI) Vendor— Affected before 0.8.6 Fixed in 0.8.6 Patch available GHSA-jjp7-g2jw-wh3j

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:openwebui:open_webui:*:*:*:*:*:*:*:*before 0.8.6Vulnerableopen-webui
  • cpe:2.3:a:openwebui:open_webui:*:*:*:*:*:*:*:* Versions before 0.8.6 Vulnerable ·open-webui

Remediation

  • Fix · CNA open-webui (open-webui) Fixed in 0.8.6
  • Fix · GHSA-jjp7-g2jw-wh3j open-webui (PyPI) Fixed in 0.8.6 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-28788
  2. 2026-10-03 Alias added: GHSA-jjp7-g2jw-wh3j
  3. 2026-10-25 EPSS moved to the 50th–90th percentile

References

Exploit 1

Advisory 1

Other 2

  • TI-2024-06216 Open WebUI Arbitrary File Upload + Path Traversal CVSS 3.1HIGH 8.8
  • TI-2024-07467 Improper Authentication in open-webui/open-webui CVSS 3.1HIGH 8.2
  • TI-2026-42359 Open WebUI: Cross-user code-interpreter and tool execution via unvalidated Socket.IO event-caller session_id CVSS 3.1CRITICAL 9.0
  • TI-2026-40759 open-webui - Remote Code Execution via CORS Misconfiguration and Session Validation CVSS 4.0CRITICAL 9.0
  • TI-2024-07431 Cross-site Scripting (XSS) in open-webui/open-webui CVSS 3.0CRITICAL 9.0
  • TI-2026-60021 Open WebUI: Same-origin XSS to account takeover via terminal port-preview iframe hardcoding allow-same-origin CVSS 3.1HIGH 8.7
See all 154 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences