CVE-2026-56400 CRITICAL

CVE-2026-56400: open-webui - Remote Code Execution via CORS Misconfiguration and Session Validation

Vendor Open-Webui
Product open-webui
Weakness CWE-613 · Insufficient session expiration
Published July 15, 2026
Last update July 15, 2026

CVSS base score

9.0/10
Attack vector Network
Attack complexity High
Privileges required None
User interaction
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

What the vulnerability does

01Description

open-webui before 0.3.14 contains a cross-origin resource sharing misconfiguration allowing arbitrary origins with allow_origins=* and authenticated requests to the /api/v1/functions endpoint. Attackers can execute arbitrary code on the openwebui instance by crafting malicious cross-site requests from attacker-controlled websites when an admin user visits them.

Key dates

02Disclosure timeline

July 15, 2026 CVE published