CVE-2026-45339 — Open WebUI is a self-hosted artificial intelligence
CVE-2026-45339 — Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, Open WebUI allows admins to restrict which API endpoints an API key can access. When an API key is restricted from /api/v1/messages, requests using the Authorization: B
What This Means For You
- If your environment is affected by CWE-863, review your exposure and prioritize patching based on your environment. Monitor vendor advisories for CVE-2026-45339 updates and patches.
Related ATT&CK Techniques
🛡️ Detection Rules
2 rules · 6 SIEM formats2 detection rules auto-generated for this incident, mapped to MITRE ATT&CK. Sigma YAML is free — export to any SIEM format via the Intel Bot.
CVE-2026-45339 - Open WebUI API Key Bypass via x-api-key Header
title: CVE-2026-45339 - Open WebUI API Key Bypass via x-api-key Header
id: scw-2026-05-15-ai-1
status: experimental
level: high
description: |
Detects exploitation of CVE-2026-45339 where an API key restricted from the /api/v1/messages endpoint is used via the 'x-api-key' header, bypassing the restriction. This indicates an attempt to access restricted AI model functionalities.
author: SCW Feed Engine (AI-generated)
date: 2026-05-15
references:
- https://shimiscyberworld.com/posts/nvd-CVE-2026-45339/
tags:
- attack.initial_access
- attack.t1190
logsource:
category: webserver
detection:
selection:
cs-uri|contains:
- '/api/v1/messages'
cs-method:
- 'POST'
uri|contains:
- 'sk-'
condition: selection
falsepositives:
- Legitimate administrative activity
Source: Shimi's Cyber World · License & reuse
Indicators of Compromise
| ID | Type | Indicator |
|---|---|---|
| CVE-2026-45339 | vulnerability | CVE-2026-45339 |
| CWE-863 | weakness | CWE-863 |
Written by SCW Vulnerability Desk
Source & Attribution
| Source Platform | NVD |
| Channel | National Vulnerability Database |
| Published | May 15, 2026 at 23:16 UTC |
This content was curated and summarized by Shimi's Cyber World for informational purposes. It is not copied or republished in full. All intellectual property rights remain with the original author and source.
Believe this infringes your rights? Submit a takedown request.
Related coverage
radare2 Use-After-Free (CVE-2026-8696) Risks Denial of Service, RCE
CVE-2026-8696 — radare2 6.1.5 contains a use-after-free vulnerability in the gdbr_pids_list() function within the GDB client core that allows remote attackers to cause a denial...
CVE-2026-45675: Open WebUI Vulnerable to Admin Role Race Condition
CVE-2026-45675 — Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, he LDAP and OAuth authentication flows use...
CVE-2026-45671: Open WebUI File Deletion Flaw Impacts Self-Hosted AI
CVE-2026-45671 — Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, any authenticated user can permanently delete files...