WS-2026-0093
Published:September 27, 2026
Updated:October 07, 2026
Open WebUI 0.11.1 through 0.11.3: the DOCX attachment preview (src/lib/components/common/DocxPreview.svelte) rendered uploaded documents with docx-preview defaults, which inline a document-supplied HTML part (OOXML altChunk) into an unsandboxed same-origin iframe and keep document-supplied link targets such as javascript: URLs; sanitization ran only on a fallback path. Any approved user who can upload a DOCX can embed script that runs in the Open WebUI origin when another user, for example an administrator, previews the attachment, allowing theft of the session token from localStorage and takeover of the account. Fixed in 0.11.4.
Affected Packages
https://github.com/open-webui/open-webui.git (GITHUB):
Affected version(s) >=v0.11.1 <v0.11.4Fix Suggestion:
Update to version v0.11.4open-webui (PYTHON):
Affected version(s) >=0.11.1 <0.11.4Fix Suggestion:
Update to version 0.11.4Related Resources (3)
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Contact UsCVSS v4
Base Score:
9.3
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
LOW
User Interaction
PASSIVE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
NONE
Subsequent System Confidentiality
HIGH
Subsequent System Integrity
HIGH
Subsequent System Availability
NONE
CVSS v3
Base Score:
8.7
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
NONE
Weakness Type (CWE)
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')