SB2026051156 - Multiple vulnerabilities in Open WebUI

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Main Vulnerability Database SB2026051156

SB2026051156 - Multiple vulnerabilities in Open WebUI

Published: May 11, 2026

Security Bulletin ID SB2026051156
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 5
Exploitation vector Remote access
Highest impact Data manipulation

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 5 vulnerabilities.


1) Incorrect authorization (CVE-ID: N/A)

CWE-ID: CWE-863 - Incorrect Authorization

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear


The vulnerability allows a remote user to modify note pin status without proper write authorization.

The vulnerability exists due to incorrect authorization in the POST /api/v1/notes/{id}/pin endpoint when handling pin toggle requests for shared notes. A remote user can send a crafted pin request to modify note pin status without proper write authorization.

User interaction is required, and exploitation requires read access to a shared note via explicit sharing. Only the is_pinned field can be modified.


2) Cross-site scripting (CVE-ID: N/A)

CWE-ID: CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Clear


The vulnerability allows a remote user to execute arbitrary script in a victim's browser and steal session tokens.

The vulnerability exists due to cross-site scripting in the /api/v1/audio/transcriptions upload endpoint and the /cache/{path} route when processing a user-supplied filename extension and serving the uploaded file as web content. A remote user can upload a specially crafted polyglot file and trick the victim into opening the resulting URL to execute arbitrary script in a victim's browser and steal session tokens.

User interaction is required, and the issue is exploitable by a verified user with the default-on chat.stt permission.


3) Cross-site scripting (CVE-ID: N/A)

CWE-ID: CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Clear


The vulnerability allows a remote user to execute arbitrary script in a victim's browser.

The vulnerability exists due to improper neutralization of input during web page generation in Office file preview rendering in FilePreview.svelte and FileItemModal.svelte when rendering HTML converted from user-supplied Office, Excel, or DOCX files via Svelte {@html} without DOMPurify sanitization. A remote user can upload a specially crafted document and have it rendered during file preview to execute arbitrary script in a victim's browser.

User interaction is required when a user previews the crafted file, and shared multi-user instances are especially exposed because the malicious file is stored server-side and can affect each viewer.


4) Improper Neutralization of Alternate XSS Syntax (CVE-ID: N/A)

CWE-ID: CWE-87 - Improper Neutralization of Alternate XSS Syntax

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear


The vulnerability allows a remote user to execute arbitrary JavaScript in the application's origin.

The vulnerability exists due to improper neutralization of alternate xss syntax in the profile image endpoint when processing webhook profile_image_url values containing svg data URLs. A remote user can supply a specially crafted svg payload in a webhook profile image to execute arbitrary JavaScript in the application's origin.

The Channels feature must be enabled, and user interaction is required because the malicious profile-image URL must be opened in a browser.


5) Cross-site request forgery (CVE-ID: N/A)

CWE-ID: CWE-352 - Cross-Site Request Forgery (CSRF)

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear


The vulnerability allows a remote user to cause a denial of service and disclose sensitive information.

The vulnerability exists due to improper input validation in image uploading and rendering functionality when processing user-supplied image urls. A remote user can set an image url to a malicious endpoint to cause a denial of service and disclose sensitive information.

User interaction is required, as a victim must view the compromised image, such as in a profile picture, shared chat, shared note, or model image.


Remediation

Install update from vendor's website.

References