CVE-2026-54007 Open WebUI: Cross-origin postMessage confirmation bypass via action:submit

High 7.1 Published Updated

An attacker can force an authenticated user to execute prompts and tools via cross-origin postMessage, leading to unauthorized actions and potential code execution.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
A user has to click or open something
Fix
Available

What is CVE-2026-54007?

CVE-2026-54007 is a high-severity vulnerability in Openwebui Open Webui, published on 23 Jun 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.6, the chat message listener allows non-same-origin input:prompt and action:submit messages, so an external site can set prompt text and trigger submitPrompt() in an authenticated victim session. I validated this with a cross-origin attacker page that auto-posted messages and caused unauthorized POST /api/v1/chats/new and POST /api/chat/completions requests containing attacker-controlled prompts. This enables cross-site forced actions and model/tool execution under victim privileges without consent. This vulnerability is fixed in 0.9.6.

Weakness: CWE-346

Which versions are affected by CVE-2026-54007?

3 open source packages ship an affected version, including open-webui. It affects 1 product.

PackageAffectedFixed in
open-webui PyPIAll versions0.9.6
open-webui PyPIAll versions0.9.6
open-webui PyPIAll versions0.9.6

Products include Openwebui Open Webui.

How do I fix CVE-2026-54007?

Upgrade open-webui to 0.9.6 or later.

Is CVE-2026-54007 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-54007 exists.

All Openwebui Open Webui vulnerabilities

Sources

Also known as GHSA-3vv5-8xxp-4f55, PYSEC-2026-2695.

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