CVE-2026-54009

Open WebUI: Cross-user file disclosure via /api/chat/completions image_url field

MEDIUM
6.5
CVSS Score
Published: June 23, 2026 at 04:49 PM UTC
Updated: June 27, 2026 at 11:42 AM UTC
1 product affected across 1 vendorOpen Webui

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Severity
MEDIUM6.5
Exploit prediction
EPSS 0.4%
SSVC
PoC

Description

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.6, POST /api/chat/completions accepts an image_url.url value that, when it does NOT start with http://, https://, or data:image/, is interpreted as a file id and resolved against the global file table with no ownership check. an authenticated user can therefore set image_url.url to another user's file id, the server reads that file from disk, base64-encodes it, and injects the data URI into the LLM request. the user then prompts the LLM to describe / OCR the file and reads the content back. This vulnerability is fixed in 0.9.6.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 0.9.6
Affected range stops below 0.9.6, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (1)

x_refsource_CONFIRMExploitVendor AdvisoryMitigation
Source: cverecord
https://github.com/open-webui/open-webui/security/advisories/GHSA-wch8-mhj5-9frg

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

6.5MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-639

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