Vulnerability · Published Jun 23, 2026 · Assigned by GitHub_M

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

High 7.1

In plain English

A high-severity security flaw in open-webui from open-webui. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 14% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)7.1High

Exploit odds (30 days)0.2%top 85.9% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
PyPI	open-webui	0.9.6	GHSA-3vv5-8xxp-4f55
PyPI	open-webui	0.9.6	PYSEC-2026-2695

Affected products (as reported)

Vendor	Product	Versions
open-webui	open-webui	< 0.9.6

Weakness: CWE-346 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

References

https://github.com/open-webui/open-webui/security/advisories/GHSA-3vv5-8xxp-4f55 x_refsource_CONFIRM