CVE-2026-54011 | Open WebUI is a self-hosted artificial intelligence platform… | CVSS 8.7 HIGH

Description

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.6,Open WebUI renders Mermaid blocks from Markdown files in the file preview panel and inserts the generated SVG into the DOM using innerHTML. Because Mermaid is configured with securityLevel: 'loose', attacker-controlled Mermaid content can be rendered unsafely in this flow. A working payload was validated through the Markdown preview path, resulting in JavaScript execution in the victim’s browser under the application origin. This vulnerability is fixed in 0.9.6.

Metadata

CVE ID: CVE-2026-54011
State: PUBLISHED
Assigner: GitHub_M
Reserved: 2026-06-11 16:34 UTC
Published: 2026-06-23 16:47 UTC
Last updated: 2026-06-23 17:55 UTC
Primary CWE: CWE-79
CWE-79: Improper Neutralization of Input During Web Page Gen…
Vendor / Product: open-webui / open-webui
Sources: cve.org · NVD

Severity & Metrics

8.7 HIGH CVSS 3.1

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N

SSVC — CISA Coordinator

Exploitation: PoC
Automatable: no
Tech. Impact: total

Affected products (1)

Vendor	Product	Platform	Versions
open-webui	open-webui	—	< 0.9.6

Weakness (CWE)

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

CVSS scores (1)

Score	Severity	Version	Source	Vector
8.7	HIGH	3.1	cna	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N

References (1)

https://github.com/open-webui/open-webui/security/advisories/GHSA-v8qj-hxv7-mgvv https://github.com/open-webui/open-webui/security/advisories/GHSA-v8qj-hxv7-mgvv