CVE-2026-45303
Open WebUI: Stored XSS via the HTML renedering view
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.
INFO
Published Date :
May 15, 2026, 10:16 p.m.
Last Modified :
Nov. 11, 2026, 8:10 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-45303
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 3.1 | HIGH | MITRE-CVE |
Solution
- Update Open WebUI to version 0.6.5 or later.
- Review HTML rendering and iframe sandboxing configurations.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-45303.
| URL | Resource |
|---|---|
| https://github.com/open-webui/open-webui/security/advisories/GHSA-4vrc-m9ch-6m3r | Exploit Mitigation Vendor Advisory |
| https://github.com/open-webui/open-webui/security/advisories/GHSA-4vrc-m9ch-6m3r | Exploit Mitigation Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-45303 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-45303
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-45303 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-45303 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Translated by [email protected]
Nov. 11, 2026
Action Type Old Value New Value Added Translation Title: Open-webui, Description: Open WebUI es una plataforma de inteligencia artificial autoalojada diseñada para operar completamente sin conexión. Antes de 0.6.5, a través de la vista de renderizado HTML, se pueden inyectar y ejecutar scripts. El frontend proporciona una función para visualizar el contenido HTML de un chat actual. El contenido está incrustado en un iFrame con la directiva sandbox allow-scripts allow-forms allow-same-origin. Esto significa que el contenido se coloca en una sandbox pero con permiso para ejecutar scripts y acceder a los datos del padre (p. ej., almacenamiento local). Como resultado, solo unas pocas funciones están restringidas (p. ej., mostrar un cuadro de alerta), pero, en efecto, el atributo sandbox queda en gran medida anulado. Esta vulnerabilidad se corrige en 0.6.5. -
CVE Modified by [email protected]
Jun. 17, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'open-webui', 'product': 'open-webui', 'versions': [{'status': 'affected', 'version': '< 0.6.5'}]}] -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 17, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-45303', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-05-19T12:24:29.494325Z'} -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
May. 19, 2026
Action Type Old Value New Value Added Reference https://github.com/open-webui/open-webui/security/advisories/GHSA-4vrc-m9ch-6m3r -
Initial Analysis by [email protected]
May. 18, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:openwebui:open_webui:*:*:*:*:*:*:*:* versions up to (excluding) 0.6.5 Added Reference Type GitHub, Inc.: https://github.com/open-webui/open-webui/security/advisories/GHSA-4vrc-m9ch-6m3r Types: Exploit, Mitigation, Vendor Advisory -
New CVE Received by [email protected]
May. 15, 2026
Action Type Old Value New Value Added 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. Added CVSS V3.1 AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:N Added CWE CWE-79 Added Reference https://github.com/open-webui/open-webui/security/advisories/GHSA-4vrc-m9ch-6m3r