Cyber Resilience

CVE-2026-45671

HighPublic PoC

Published: 15 May 2026

Published
15 May 2026
Modified
19 May 2026
KEV Added
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Patch
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CVSS Score v3.1 8.0 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.0004 14.4th percentile
Risk Priority 16 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-45671 is a high-severity Authorization Bypass Through User-Controlled Key (CWE-639) vulnerability in Openwebui Open Webui. Its CVSS base score is 8.0 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 14.4th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

This vulnerability is AI-related — categorised as LLM Application Platforms; in the Data-Related Vulnerabilities risk domain.

EU & UK References

Vulnerability details

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 owned by other users via DELETE /api/v1/files/{id} when the target file is referenced in any shared chat.…

more

The has_access_to_file() authorization gate unconditionally grants access through its shared-chat branch. It checks neither the requesting user's identity nor the type of operation being performed. File UUIDs (which would otherwise be impractical to guess) are disclosed to any user with read access to a knowledge base via GET /api/v1/knowledge/{id}/files. This vulnerability is fixed in 0.9.0.

CWE(s)
CWE-639

AI Security AnalysisAI

AI Category
LLM Application Platforms
Risk Domain
Data-Related Vulnerabilities
OWASP Top 10 for LLMs 2025
None mapped
Classification Reason
Matched keywords: artificial intelligence, open webui

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1485 Data Destruction Impact
Adversaries may destroy data and files on specific systems or in large numbers on a network to interrupt availability to systems, services, and network resources.
attack.mitre.org →
Why these techniques?

Authz bypass (CWE-639/IDOR) in web API directly enables exploitation of the public/self-hosted app (T1190) to perform unauthorized file deletion (T1485).

Confidence: MEDIUM · MITRE ATT&CK Enterprise v18.1

CVEs Like This One

CVE-2026-45398Same product: Openwebui Open Webui
CVE-2026-28788Same product: Openwebui Open Webui
CVE-2026-44570Same product: Openwebui Open Webui
CVE-2026-45349Same product: Openwebui Open Webui
CVE-2026-45402Same product: Openwebui Open Webui
CVE-2026-44567Same product: Openwebui Open Webui
CVE-2026-44551Same product: Openwebui Open Webui
CVE-2026-45400Same product: Openwebui Open Webui
CVE-2026-45350Same product: Openwebui Open Webui
CVE-2026-45331Same product: Openwebui Open Webui

Affected Assets

openwebui
open webui
≤ 0.9.0

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

AC-24 Access Control Decisions
addresses: CWE-639

Per-request decision making makes it harder to bypass authorization using user-controlled keys without proper validation in the decision process.

AC-3 Access Enforcement
addresses: CWE-639

Consistent enforcement of approved authorizations makes bypassing via user-controlled keys ineffective.

References