CVE-2026-45303

Open WebUI: Stored XSS via the HTML renedering view

HIGH
7.7
CVSS Score
Published: May 15, 2026 at 09:21 PM UTC
Updated: June 17, 2026 at 10:51 AM UTC
1 product affected across 1 vendorOpen Webui

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Severity
HIGH7.7
Exploit prediction
EPSS 0.2%
SSVC
PoC

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 0.6.5
Affected range stops below 0.6.5, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (1)

x_refsource_CONFIRMExploitMitigationVendor Advisory
Source: cverecord
https://github.com/open-webui/open-webui/security/advisories/GHSA-4vrc-m9ch-6m3r

SSVC — Action Prioritization

SSVCPoCNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.7HIGHGitHub_M
Attack Vector
NETWORK
Complexity
HIGH
Privileges
LOW
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-79

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