Open WebUI vulnerable to Stored XSS via iFrame embeds in response messages

published 2026-02-19 8 mo ago modified 2026-07-13 3 mo ago also GHSA-vjm7-m4xh-7wrc , PYSEC-2026-2760 , EUVD-2026-7981

cvss: 7.3; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 14%
public exploits: 0; none known

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to version 0.6.44, aanually modifying chat history allows setting the `embeds` property on a response message, the content of which is loaded into an iFrame with a sandbox that has `allow-scripts` and `allow-same-origin` set, ignoring the "iframe Sandbox Allow Same Origin" configuration. This enables stored XSS on the affected chat. This also triggers when the chat is in the shared format. The result is a shareable link containing the payload that can be distributed to any other users on the instance. Version 0.6.44 fixes the issue.

Patch / fix

fixed in 2

pypi open-webui 0.6.44
openwebui open_webui 0.6.44

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 8 mo ago (2026-02-19)

Exploit prediction

0.23% chance of exploitation in the next 30 days, higher than 14% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/open-webui/open-webui/security/advisories/GHSA-vjm7-m4xh-7wrc referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.1	7.3	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N
NVD	3.1	5.4	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
OSV	3.1	7.3	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N
GitHub	3.1	7.3	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N

Affected packages

ecosystem	package	affected	fixed in
pypi	open-webui	<0.6.44	0.6.44

Affected products

open-webui open-webui

Classification

Weakness

CWE-79 Improper Neutralization of Input During Web Page Generation

References

github.com /open-webui/open-webui/security/advisories/GHSA-vjm7-m4xh-7wrc
web, exploit, vendor-advisory
github.com /open-webui/open-webui/blob/6f1486ffd0cb288d0e21f41845361924e0d742b3/src/lib/components/chat/Messages/Response
web, product
nvd.nist.gov /vuln/detail/CVE-2026-26193
advisory
github.com /open-webui/open-webui
package
pypi.org /project/open-webui
package
github.com /advisories/GHSA-vjm7-m4xh-7wrc
advisory

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary