What’s Vulnerable › Vulnerabilities

CVE-2026-26193: Open WebUI vulnerable to Stored XSS via iFrame embeds in response messages

• Severity: medium (CVSS 5.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-02-19 · updated 2026-06-17
• Weakness: CWE-79

Description

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to version 0.6.44, aanually modifying chat history allows setting the `embeds` property on a response message, the content of which is loaded into an iFrame with a sandbox that has `allow-scripts` and `allow-same-origin` set, ignoring the "iframe Sandbox Allow Same Origin" configuration. This enables stored XSS on the affected chat. This also triggers when the chat is in the shared format. The result is a shareable link containing the payload that can be distributed to any other users on the instance. Version 0.6.44 fixes the issue.

Affected products

• open-webui: before 0.6.44 — fixed in 0.6.44

How to fix

Upgrade to a fixed version: open-webui 0.6.44. Check the vendor advisory for mitigations.

References

• https://github.com/open-webui/open-webui/blob/6f1486ffd0cb288d0e21f41845361924e0d742b3/src/lib/components/chat/Messages/ResponseMessage.svelte#L689-L703
• https://github.com/open-webui/open-webui/security/advisories/GHSA-vjm7-m4xh-7wrc

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