Vulnerability · Published May 15, 2026 · Assigned by GitHub_M

CVE-2026-45303Open WebUI: Stored XSS via the HTML renedering view

High 7.7

In plain English

A high-severity cross-site scripting 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 13% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.7High

Exploit odds (30 days)0.2%top 86.7% 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 0.6.5, through the HTML rendering view, scripts can be injected and executed. The frontend provides a function to visualize the HTML content of a current chat. The content is embedded in an iFrame with the allow-scripts allow-forms allow-same-origin sandbox directive. This means that the content is placed in a sandbox but with permission to execute scripts and access the parent’s data (e.g., local storage). As a result, only a few functions are restricted (e.g., displaying an alert box), but in effect, the sandbox attribute is largely nullified. This vulnerability is fixed in 0.6.5.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
PyPI	open-webui	0.6.5	GHSA-4vrc-m9ch-6m3r
PyPI	open-webui	0.6.5	PYSEC-2026-2704

Affected products (as reported)

Vendor	Product	Versions
open-webui	open-webui	< 0.6.5

Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:N

References

https://github.com/open-webui/open-webui/security/advisories/GHSA-4vrc-m9ch-6m3r x_refsource_CONFIRM